Led lamp

ABSTRACT

A lamp comprises an enclosure comprising a reflector and a lens where the reflector is made of thermally conductive material. A base is coupled to the enclosure. An LED is located in the enclosure and emits light when energized through an electrical path from the base. A heat sink comprises a heat dissipating portion that may be at least partially exposed to the ambient environment and a heat conducting portion that is thermally coupled to the LED. The reflector is thermally coupled to the heat sink and is exposed to the exterior of the lamp such that heat from the heat sink may be dissipated to the ambient environment at least partially through the reflector.

This application is a continuation-in-part (CIP) of U.S. applicationSer. No. 13/774,078, as filed on Feb. 22, 2013, which is incorporated byreference herein in its entirety, and which is a continuation-in-part(CIP) of U.S. application Ser. No. 13/467,670, as filed on May 9, 2012,which is incorporated by reference herein in its entirety, and which isa continuation-in-part (CIP) of U.S. application Ser. No. 13/446,759, asfiled on Apr. 13, 2012, which is incorporated by reference herein in itsentirety.

This application also claims benefit of priority under 35 U.S.C. §119(e)to the filing date of U.S. Provisional Application No. 61/738,668, asfiled on Dec. 18, 2012, which is incorporated by reference herein in itsentirety; and to the filing date of U.S. Provisional Application No.61/712,585, as filed on Oct. 11, 2012, which is incorporated byreference herein in its entirety; and to the filing date of U.S.Provisional Application No. 61/716,818, as filed on Oct. 22, 2012, whichis incorporated by reference herein in its entirety.

BACKGROUND

Light emitting diode (LED) lighting systems are becoming more prevalentas replacements for older lighting systems. LED systems are an exampleof solid state lighting (SSL) and have advantages over traditionallighting solutions such as incandescent and fluorescent lighting becausethey use less energy, are more durable, operate longer, can be combinedin multi-color arrays that can be controlled to deliver virtually anycolor light, and generally contain no lead or mercury. A solid-statelighting system may take the form of a lighting unit, light fixture,light bulb, or a “lamp.”

An LED lighting system may include, for example, a packaged lightemitting device including one or more light emitting diodes (LEDs),which may include inorganic LEDs, which may include semiconductor layersforming p-n junctions and/or organic LEDs (OLEDs), which may includeorganic light emission layers. Light perceived as white or near-whitemay be generated by a combination of red, green, and blue (“RGB”) LEDs.Output color of such a device may be altered by separately adjustingsupply of current to the red, green, and blue LEDs. Another method forgenerating white or near-white light is by using a lumiphor such as aphosphor. Still another approach for producing white light is tostimulate phosphors or dyes of multiple colors with an LED source. Manyother approaches can be taken.

An LED lamp may be made with a form factor that allows it to replace astandard incandescent bulb, or any of various types of fluorescentlamps. LED lamps often include some type of optical element or elementsto allow for localized mixing of colors, collimate light, or provide aparticular light pattern. Sometimes the optical element also serves asan envelope or enclosure for the electronics and or the LEDs in thelamp.

Since, ideally, an LED lamp designed as a replacement for a traditionalincandescent or fluorescent light source needs to be self-contained; apower supply is included in the lamp structure along with the LEDs orLED packages and the optical components. A heatsink is also often neededto cool the LEDs and/or power supply in order to maintain appropriateoperating temperature.

SUMMARY OF THE INVENTION

In some embodiments a lamp comprises an optically transmissive enclosureand a base. The enclosure comprises a reflector and a lens where thereflector is made of thermally conductive material. At least one LED islocated in the enclosure and is operable to emit light when energizedthrough an electrical path from the base. A heat sink comprises a heatdissipating portion that is at least partially exposed to the ambientenvironment and a heat conducting portion that is thermally coupled tothe at least one LED. The reflector is thermally coupled to the heatsink and is exposed to the exterior of the lamp such that heat from theheat sink may be dissipated to the ambient environment at leastpartially through the reflector.

The reflector may be made of metal such as aluminum. The reflector maycomprise a reflective surface that generates a directional lightpattern. The reflective surface may be parabolic. The reflective surfacemay be metalized. The reflector may be secured to the heat sink. Thereflector may be secured to the heat sink using deformable nubs. Thenubs may be inserted through apertures in the reflector and may bedeformed to create a head that retains the reflector against the heatsink. The nubs may be formed integrally with the heat sink. A secondaryreflector may reflect light from the at least one LED to the reflector.The secondary reflector may be located in a chamber formed by thereflector and the lens. The secondary reflector may be located inside ofthe lens. The secondary reflector may be inserted molded in the lens.The heat sink may extend between the enclosure and the base.

In some embodiments a lamp comprises an optically transmissive enclosureand a base. The enclosure comprises a reflector housing made of athermally conductive material and a reflector located in the enclosure.A lens emits light from the enclosure. At least one LED is located inthe enclosure and is operable to emit light when energized through anelectrical path from the base. A heat sink comprises a first part thatis located inside of the enclosure and that is thermally coupled to theat least one LED and a second part that is thermally coupled to thefirst part. The reflector housing is thermally coupled to the heat sinkand is exposed to the exterior of the lamp such that heat from the heatsink may be dissipated to the ambient environment at least partiallythrough the reflector housing.

The reflector may comprise a reflective surface that generates a lightpattern. The reflector housing may comprise a flange that surrounds aportion of the heat sink. The flange may be secured to the heat sinkusing a friction fit. The flange may be heat shrunk over the heat sink.The flange may be crimped to the heat sink. The flange may be swaged tothe heat sink. The heat sink may be disposed between the enclosure andthe base. The at least one LED may comprise a plurality of LEDs arrangedsuch that the plurality of LEDs are disposed about the periphery of thefirst part in a band and face outwardly toward the enclosure to create asource of the light that appears as a glowing filament. At least some ofthe LEDs may emit light laterally. A clamping structure may clamp the atleast one LED to the heat sink. The clamping structure may comprise apair of extensions on the LED assembly that engage mating receptaclesformed on the heat sink. The plurality of LEDs may be mounted on asubmount where the clamping structure comprises a pair of extensionsextending from the submount that engage mating receptacles formed on theheat sink.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of an embodiment of a lamp of the invention.

FIG. 2 is a section view taken along line A-A of FIG. 1.

FIG. 3 is a side view of the lamp of FIG. 1.

FIG. 4 is a section view taken along line B-B of FIG. 3.

FIG. 5 is an exploded perspective view of the lamp of FIG. 1.

FIGS. 6 through 9 are exploded plan views of the lamp of FIG. 1 atdifferent orientations of the lamp.

FIG. 10 is a section view similar to FIG. 2.

FIG. 11 is a section view similar to FIG. 4.

FIG. 12 is an exploded view showing an embodiment of the heat sink andLED assembly of FIG. 1.

FIG. 13 is a plan view showing an embodiment of the electricalinterconnect of FIG. 1.

FIG. 14 is a side view showing an embodiment of the electricalinterconnect of FIG. 1.

FIG. 15 is a perspective view of the heat sink of FIG. 1.

FIG. 16 is a perspective view of the LED assembly of FIG. 1.

FIG. 17 is a plan view showing another embodiment of the electricalinterconnect.

FIG. 18 is a plan view showing still another embodiment of theelectrical interconnect.

FIG. 19 is a side view of an embodiment of a MCPCB submount usable inembodiments of the lamp of the invention.

FIG. 20 is an end view of the embodiment of a MCPCB submount of FIG. 19.

FIGS. 21 through 23 are exploded plan views of an alternate embodimentof the lamp of the invention at different orientations of the lamp.

FIG. 24 is a front view of the embodiment of the lamp of FIG. 21.

FIG. 25 is a section view taken along line B-B of FIG. 24.

FIG. 26 is a more detailed section view taken along line B-B of FIG. 24.

FIGS. 27 through 29 are exploded plan views of an alternate embodimentof the lamp of the invention at different orientations of the lamp.

FIG. 30 is a front view of an embodiment of a lamp of FIG. 27.

FIG. 31 is a section view taken along line B-B of FIG. 30.

FIG. 32 is a side view of an embodiment of a reflector.

FIG. 33 is a top view of the reflector of FIG. 32.

FIG. 34 is a perspective view of the reflector of FIG. 32.

FIG. 35 is a top view showing the reflector and LED assembly and heatsink of the embodiment of FIG. 27-32.

FIG. 36 is a side view of the assembly of FIG. 35.

FIG. 37 is a bottom view of the assembly of FIG. 35.

FIGS. 38 through 40 are exploded plan views of an alternate embodimentof the lamp of the invention at different orientations of the lamp.

FIG. 41 is a front view of the embodiment of the lamp of FIG. 38.

FIG. 42 is a section view taken along line B-B of FIG. 41.

FIG. 43 is a perspective view of an embodiment of a reflector.

FIG. 44 is a top view of the reflector of FIG. 43.

FIG. 45 is a side view of the reflector of FIG. 43.

FIG. 46 is a bottom view of the reflector of FIG. 43.

FIG. 47 is a top view showing the reflector and LED assembly and heatsink of the embodiment of FIG. 38-42.

FIG. 48 is a side view of the assembly of FIG. 47.

FIG. 49 is a bottom view of the assembly of FIG. 47.

FIGS. 50 through 52 are exploded plan views of an alternate embodimentof the lamp of the invention at different orientations of the lamp.

FIG. 53 is a front view of the embodiment of the lamp of FIG. 50.

FIG. 54 is a section view taken along line B-B of FIG. 53.

FIG. 55 is a side view of an embodiment of a reflector.

FIG. 56 is a perspective view of the reflector of FIG. 55.

FIG. 57 is a top view of the reflector of FIG. 55.

FIG. 58 is a top view showing the reflector and LED assembly and heatsink of the embodiment of FIG. 50-54.

FIG. 59 is a side view of the assembly of FIG. 58.

FIG. 60 is a bottom view of the assembly of FIG. 58.

FIG. 61 is a cross-sectional view of a lens according to exampleembodiments of the present invention.

FIG. 62 is a magnified, cross-sectional view of the lens depicted inFIG. 61.

FIG. 63 is a magnified, cross-sectional view of the lens depicted inFIG. 61.

FIG. 64 is a magnified, cross-sectional view of the lens depicted inFIG. 61.

FIGS. 65 through 67 are exploded plan views of an alternate embodimentof the lamp of the invention at different orientations of the lamp.

FIG. 68 is a front view of the embodiment of the lamp of FIG. 65.

FIG. 69 is a section view taken along line B-B of FIG. 68.

FIG. 70 is a side view of an embodiment of a reflector.

FIG. 71 is a top view of the reflector of FIG. 70.

FIG. 72 is a perspective view of the reflector of FIG. 70.

FIG. 73 is a top view showing the reflector and LED assembly and heatsink of the embodiment of FIG. 65-69.

FIG. 74 is a side view of the assembly of FIG. 73.

FIG. 75 is a bottom view of the assembly of FIG. 73.

FIG. 76 is a perspective view of an embodiment of a reflector, heat sinkand base.

FIG. 77 is a perspective view of the embodiment of the reflector of FIG.76, heat sink and base in a different orientation.

FIG. 78 is a perspective view of the reflector of FIG. 76.

FIG. 79 is a perspective view of one portion of the reflector of FIG.76.

FIG. 80 is a side view of one portion of the reflector of FIG. 76.

FIG. 81 is a front view of the reflector of FIG. 76 in a disassembledcondition.

FIG. 82 is an alternate side view of one portion of the reflector ofFIG. 76.

FIG. 83 is a top view of one portion of the reflector of FIG. 76.

FIG. 84 is a bottom view of one portion of the reflector of FIG. 76.

FIG. 85 is a section view of an alternate embodiment of the lamp of theinvention.

FIG. 86 is a section view of an alternate embodiment of a directionallamp.

FIG. 87 is a section view of the lamp of FIG. 86 useful in explaining amethod of constructing the lamp.

FIG. 88 is a section view of another alternate embodiment of adirectional lamp.

FIG. 89 is a section view of yet another alternate embodiment of adirectional lamp.

FIG. 90 is a section view of still another alternate embodiment of adirectional lamp.

FIG. 91 is a section view of another alternate embodiment of adirectional lamp.

FIG. 92 is a section view of yet another alternate embodiment of adirectional lamp.

DETAILED DESCRIPTION

Embodiments of the present invention now will be described more fullyhereinafter with reference to the accompanying drawings, in whichembodiments of the invention are shown. This invention may, however, beembodied in many different forms and should not be construed as limitedto the embodiments set forth herein. Rather, these embodiments areprovided so that this disclosure will be thorough and complete, and willfully convey the scope of the invention to those skilled in the art.Like numbers refer to like elements throughout.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of the present invention. Asused herein, the term “and/or” includes any and all combinations of oneor more of the associated listed items.

It will be understood that when an element such as a layer, region orsubstrate is referred to as being “on” or extending “onto” anotherelement, it can be directly on or extend directly onto the other elementor intervening elements may also be present. In contrast, when anelement is referred to as being “directly on” or extending “directlyonto” another element, there are no intervening elements present. Itwill also be understood that when an element is referred to as being“connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present.

Relative terms such as “below” or “above” or “upper” or “lower” or“horizontal” or “vertical” or “top” or “bottom” may be used herein todescribe a relationship of one element, layer or region to anotherelement, layer or region as illustrated in the figures. It will beunderstood that these terms are intended to encompass differentorientations of the device in addition to the orientation depicted inthe figures.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”“comprising,” “includes” and/or “including” when used herein, specifythe presence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms used herein should be interpreted ashaving a meaning that is consistent with their meaning in the context ofthis specification and the relevant art and will not be interpreted inan idealized or overly formal sense unless expressly so defined herein.

Unless otherwise expressly stated, comparative, quantitative terms suchas “less” and “greater”, are intended to encompass the concept ofequality. As an example, “less” can mean not only “less” in thestrictest mathematical sense, but also, “less than or equal to.”

The terms “LED” and “LED device” as used herein may refer to anysolid-state light emitter. The terms “solid state light emitter” or“solid state emitter” may include a light emitting diode, laser diode,organic light emitting diode, and/or other semiconductor device whichincludes one or more semiconductor layers, which may include silicon,silicon carbide, gallium nitride and/or other semiconductor materials, asubstrate which may include sapphire, silicon, silicon carbide and/orother microelectronic substrates, and one or more contact layers whichmay include metal and/or other conductive materials. A solid-statelighting device produces light (ultraviolet, visible, or infrared) byexciting electrons across the band gap between a conduction band and avalence band of a semiconductor active (light-emitting) layer, with theelectron transition generating light at a wavelength that depends on theband gap. Thus, the color (wavelength) of the light emitted by asolid-state emitter depends on the materials of the active layersthereof. In various embodiments, solid-state light emitters may havepeak wavelengths in the visible range and/or be used in combination withlumiphoric materials having peak wavelengths in the visible range.Multiple solid state light emitters and/or multiple lumiphoric materials(i.e., in combination with at least one solid state light emitter) maybe used in a single device, such as to produce light perceived as whiteor near white in character. In certain embodiments, the aggregatedoutput of multiple solid-state light emitters and/or lumiphoricmaterials may generate warm white light output having a colortemperature range of from about 2200K to about 6000K.

Solid state light emitters may be used individually or in combinationwith one or more lumiphoric materials (e.g., phosphors, scintillators,lumiphoric inks) and/or optical elements to generate light at a peakwavelength, or of at least one desired perceived color (includingcombinations of colors that may be perceived as white). Inclusion oflumiphoric (also called ‘luminescent’) materials in lighting devices asdescribed herein may be accomplished by direct coating on solid statelight emitter, adding such materials to encapsulants, adding suchmaterials to lenses, by embedding or dispersing such materials withinlumiphor support elements, and/or coating such materials on lumiphorsupport elements. Other materials, such as light scattering elements(e.g., particles) and/or index matching materials, may be associatedwith a lumiphor, a lumiphor binding medium, or a lumiphor supportelement that may be spatially segregated from a solid state emitter.

Embodiments of the present invention provide a solid-state lamp withcentralized light emitters, more specifically, LEDs. Multiple LEDs canbe used together, forming an LED array. The LEDs can be mounted on orfixed within the lamp in various ways. In at least some exampleembodiments, a submount is used. The LEDs are disposed at or near thecentral portion of the structural envelope of the lamp. Since the LEDarray may be configured in some embodiments to reside centrally withinthe structural envelope of the lamp, a lamp can be constructed so thatthe light pattern is not adversely affected by the presence of a heatsink and/or mounting hardware, or by having to locate the LEDs close tothe base of the lamp. It should also be noted that the term “lamp” ismeant to encompass not only a solid-state replacement for a traditionalincandescent bulb as illustrated herein, but also replacements forfluorescent bulbs, replacements for complete fixtures, and any type oflight fixture that may be custom designed as a solid state fixture formounting on walls, in or on ceilings, on posts, and/or on vehicles.

FIGS. 1 through 11 show a lamp, 100, according to some embodiments ofthe present invention. Lamp 100 may be used as an A-series lamp with anEdison base 102, more particularly; lamp 100 is designed to serve as asolid-state replacement for an A19 incandescent bulb. The Edison base102 as shown and described herein may be implemented through the use ofan Edison connector 103 and a plastic form. The LEDs 127 in the LEDarray 128 may comprise an LED die disposed in an encapsulant such assilicone, and LEDs which are encapsulated with a phosphor to providelocal wavelength conversion, as will be described later when variousoptions for creating white light are discussed. The LEDs 127 of LEDarray 128 are mounted on a submount 129 and are operable to emit lightwhen energized through an electrical connection. In the presentinvention the term “submount” is used to refer to the support structurethat supports the individual LEDs or LED packages and in one embodimentcomprises a printed circuit board or “PCB” although it may compriseother structures such as a lead frame extrusion or the like orcombinations of such structures. In some embodiments, a driver or powersupply may be included with the LED array on the submount. In some casesthe driver may be formed by components on PCB 80. While a lamp havingthe size and form factor of a standard-sized household incandescent bulbis shown, the lamp may have other the sizes and form factors. Forexample, the lamp may be a PAR-style lamp such as a replacement for aPAR-38 incandescent bulb or a BR-style incandescent bulb.

Enclosure 112 is, in some embodiments, made of glass, quartz,borosilicate, silicate, polycarbonate, other plastic or other suitablematerial. The enclosure may be of similar shape to that commonly used inhousehold incandescent bulbs. In some embodiments, the glass enclosureis coated on the inside with silica 113, providing a diffuse scatteringlayer that produces a more uniform far field pattern. The enclosure mayalso be etched, frosted or coated. Alternatively, the surface treatmentmay be omitted and a clear enclosure may be provided. The enclosure mayalso be provided with a shatter proof or shatter resistant coating. Itshould also be noted that in this or any of the embodiments shown here,the optically transmissive enclosure or a portion of the opticallytransmissive enclosure could be coated or impregnated with phosphor or adiffuser. The glass enclosure 112 may have a traditional bulb shapehaving a globe shaped main body 114 that tapers to a narrower neck 115.

A lamp base 102 such as an Edison base functions as the electricalconnector to connect the lamp 100 to an electrical socket or otherconnector. Depending on the embodiment, other base configurations arepossible to make the electrical connection such as other standard basesor non-traditional bases. Base 102 may include the electronics 110 forpowering lamp 100 and may include a power supply and/or driver and formall or a portion of the electrical path between the mains and the LEDs.Base 102 may also include only part of the power supply circuitry whilesome smaller components reside on the submount. With the embodiment ofFIG. 1, as with many other embodiments of the invention, the term“electrical path” can be used to refer to the entire electrical path tothe LED array 128, including an intervening power supply disposedbetween the electrical connection that would otherwise provide powerdirectly to the LEDs and the LED array, or it may be used to refer tothe connection between the mains and all the electronics in the lamp,including the power supply. The term may also be used to refer to theconnection between the power supply and the LED array. Electricalconductors run between the LED assembly 130 and the lamp base 102 tocarry both sides of the supply to provide critical current to the LEDs127 as will be described.

The LED assembly 130 may be implemented using a printed circuit board(“PCB”) and may be referred by in some cases as an LED PCB. In someembodiments the LED PCB comprises the submount 129. The lamp 100comprises a solid-state lamp comprising a LED assembly 130 with lightemitting LEDs 127. Multiple LEDs 127 can be used together, forming anLED array 128. The LEDs 127 can be mounted on or fixed within the lampin various ways. In at least some example embodiments, a submount 129 isused. The LEDs 127 in the LED array 128 include LEDs which may comprisean LED die disposed in an encapsulant such as silicone, and LEDs whichmay be encapsulated with a phosphor to provide local wavelengthconversion, as will be described later when various options for creatingwhite light are discussed. A wide variety of LEDs and combinations ofLEDs may be used in the LED assembly 130 as described herein. The LEDs127 of the LED array 128 are operable to emit light when energizedthrough an electrical connection. An electrical path runs between thesubmount 129 and the lamp base 102 to carry both sides of the supply toprovide critical current to the LEDs 127.

In some embodiments, a driver and/or power supply are included with theLED array 128 on the submount 129. In other embodiments the driverand/or power supply are included in the base 102 as shown. The powersupply and drivers may also be mounted separately where components ofthe power supply are mounted in the base 102 and the driver is mountedwith the submount 129 in the enclosure 112. Base 102 may include a powersupply or driver and form all or a portion of the electrical pathbetween the mains and the LEDs 127. The base 102 may also include onlypart of the power supply circuitry while some smaller components resideon the submount 129. In some embodiments any component that goesdirectly across the AC input line may be in the base 102 and othercomponents that assist in converting the AC to useful DC may be in theglass enclosure 112. In one example embodiment, the inductors andcapacitor that form part of the EMI filter are in the Edison base.Suitable power supplies and drivers are described in U.S. patentapplication Ser. No. 13/462,388 filed on May 2, 2012 and titled “DriverCircuits for Dimmable Solid State Lighting Apparatus” which isincorporated herein by reference in its entirety; U.S. patentapplication Ser. No. 12/775,842 filed on May 7, 2010 and titled “ACDriven Solid State Lighting Apparatus with LED String Including SwitchedSegments” which is incorporated herein by reference in its entirety;U.S. patent application Ser. No. 13/192,755 filed Jul. 28, 2011 titled“Solid State Lighting Apparatus and Methods of Using Integrated DriverCircuitry” which is incorporated herein by reference in its entirety;U.S. patent application Ser. No. 13/339,974 filed Dec. 29, 2011 titled“Solid-State Lighting Apparatus and Methods Using Parallel-ConnectedSegment Bypass Circuits” which is incorporated herein by reference inits entirety; U.S. patent application Ser. No. 13/235,103 filed Sep. 16,2011 titled “Solid-State Lighting Apparatus and Methods Using EnergyStorage” which is incorporated herein by reference in its entirety; U.S.patent application Ser. No. 13/360,145 filed Jan. 27, 2012 titled “SolidState Lighting Apparatus and Methods of Forming” which is incorporatedherein by reference in its entirety; U.S. patent application Ser. No.13/338,095 filed Dec. 27, 2011 titled “Solid-State Lighting ApparatusIncluding an Energy Storage Module for Applying Power to a Light SourceElement During Low Power Intervals and Methods of Operating the Same”which is incorporated herein by reference in its entirety; U.S. patentapplication Ser. No. 13/338,076 filed Dec. 27, 2011 titled “Solid-StateLighting Apparatus Including Current Diversion Controlled by LightingDevice Bias States and Current Limiting Using a Passive ElectricalComponent” which is incorporated herein by reference in its entirety;and U.S. patent application Ser. No. 13/405,891 filed Feb. 27, 2012titled “Solid-State Lighting Apparatus and Methods Using Energy Storage”which is incorporated herein by reference in its entirety.

The AC to DC conversion may be provided by a boost topology to minimizelosses and therefore maximize conversion efficiency. The boost supply isconnected to high voltage LEDs operating at greater than 200V. Otherembodiments are possible using different driver configurations, or aboost supply at lower voltages.

In some embodiments a gas movement device may be provided within theenclosure 112 to increase the heat transfer between the LEDs 127 and LEDassembly 130 and heat sink 149. The movement of the gas over the LEDassembly 130 moves the gas boundary layer on the components of the LEDassembly 130. In some embodiments the gas movement device comprises asmall fan. The fan may be connected to the power source that powers theLEDs 127. While the gas movement device may comprise an electric fan,the gas movement device may comprise a wide variety of apparatuses andtechniques to move air inside the enclosure such as a rotary fan, apiezoelectric fan, corona or ion wind generator, synjet diaphragm pumpsor the like.

The LED assembly 130 comprises a submount 129 arranged such that the LEDarray 128 is substantially in the center of the enclosure 112 such thatthe LED's 127 are positioned at the approximate center of enclosure 112.As used herein the terms “center of the enclosure” and “optical centerof the enclosure” refers to the vertical position of the LEDs in theenclosure as being aligned with the approximate largest diameter area ofthe globe shaped main body 114. “Vertical” as used herein means alongthe longitudinal axis of the bulb where the longitudinal axis extendsfrom the base to the free end of the bulb as represented for example byline A-A in FIG. 1. In one embodiment, the LED array 128 is arranged inthe approximate location that the visible glowing filament is disposedin a standard incandescent bulb. The terms “center of the enclosure” and“optical center of the enclosure” do not necessarily mean the exactcenter of the enclosure and are used to signify that the LEDs arelocated along the longitudinal axis of the lamp at a position betweenthe ends of the enclosure near a central portion of the enclosure.

Referring to FIGS. 19 and 20, in some embodiments, the submount 129 maycomprise a PCB, metal core board, metal core printed circuit board orother similar structure. The submount may be made of a thermallyconductive material. In some embodiments the thickness of the submountmay be about 1 mm-2.0 mm thick. For example the thickness may be about1.6 mm. In other embodiments a copper or copper based lead frame may beused. Such a lead frame may have a thickness of about 0.25-1.0 mm, forexample, 0.25 mm or 0.5 mm. In other embodiments, other dimensionsincluding thicknesses are possible. The entire area of the submount 129may be thermally conductive such that the entire LED assembly 130transfers heat to the heat sink 149. The submount 129 comprises a firstLED mounting portion 151 that functions to mechanically and electricallysupport the LEDs 127 and a second connector portion 153 that functionsto provide thermal, electrical and mechanical connections to the LEDassembly 130. The submount 129 may be bent into the configuration of theLED assembly 130 as shown in the figures. In one embodiment, theenclosure and base are dimensioned to be a replacement for an ANSIstandard A19 bulb such that the dimensions of the lamp 100 fall withinthe ANSI standards for an A19 bulb. The dimensions may be different forother ANSI standards including, but not limited to, A21 and A23standards. While specific reference has been made with respect to anA-series lamp with an Edison base 102 the structure and assembly methodmay be used on other lamps such as a PAR-style lamp such as areplacement for a PAR-38 incandescent bulb or a BR-style lamp. In otherembodiments, the LED lamp can have any shape, including standard andnon-standard shapes.

In some embodiments, the LED lamp 100 is equivalent to a 60 Wattincandescent light bulb. In one embodiment of a 60 Watt equivalent LEDbulb, the LED assembly 130 comprises an LED array 128 of 20 XLamp® XT-EHigh Voltage white LEDs manufactured by Cree, Inc., where each XLamp®XT-E LED has a 46 V forward voltage and includes 16 DA LED chipsmanufactured by Cree, Inc. and configured in series. The XLamp® XT-ELEDs may be configured in four parallel strings with each string havingfive LEDs arranged in series, for a total of greater than 200 volts,e.g. about 230 volts, across the LED array 128. In another embodiment ofa 60 Watt equivalent LED bulb, 20 XLamp® XT-E LEDs are used where eachXT-E has a 12 V forward voltage and includes 16 DA LED chips arranged infour parallel strings of four DA chips arranged in series, for a totalof about 240 volts across the LED array 128 in this embodiment. In someembodiments, the LED lamp 100 is equivalent to a 40 Watt incandescentlight bulb. In such embodiments, the LED array 128 may comprise 10XLamp® XT-E LEDs where each XT-E includes 16 DA LED chips configured inseries. The 10 46V XLamp® XT-E® LEDs may be configured in two parallelstrings where each string has five LEDs arranged in series, for a totalof about 230 volts across the LED array 128. In other embodiments,different types of LEDs are possible, such as XLamp® XB-D LEDsmanufactured by Cree, Inc. or others. Other arrangements of chip onboard LEDs and LED packages may be used to provide LED based lightequivalent to 40, 60 and/or greater other watt incandescent light bulbs,at about the same or different voltages across the LED array 128.

In one embodiment, the LED assembly 130 has a maximum outer dimensionthat fits into the open neck 115 of the enclosure 112 during themanufacturing process and an internal dimension that is at least as wideas the width or diameter of the heat conducting portion 152 of heat sink149. In some embodiments the LED assembly 130 and heat sink 149 have acylindrical shape such that the relative dimensions of the heat sink,LED assembly and the neck may be described as diameters. In oneembodiment, the diameter of the LED assembly may be approximately 20 mm.In other embodiments some or all of these components may be other thancylindrical or round in cross-section. In such arrangements the majordimensions of these elements may have the dimensional relationships setforth above. In other embodiments, the LED assembly 130 can havedifferent cross-sectional shapes, such as triangular, square and/orother polygonal shapes with or without curved surfaces.

The base 102 comprises an electrically conductive Edison screw 103 forconnecting to an Edison socket and a housing portion 105 connected tothe Edison screw. The Edison screw 103 may be connected to the housingportion 105 by adhesive, mechanical connector, welding, separatefasteners or the like. The housing portion 105 may comprise anelectrically insulating material such as plastic. Further, the materialof the housing portion 105 may comprise a thermally conductive materialsuch that the housing portion 105 may form part of the heat sinkstructure for dissipating heat from the lamp 100. The housing portion105 and the Edison screw 103 define an internal cavity for receiving theelectronics 110 of the lamp including the power supply and/or drivers ora portion of the electronics for the lamp. The lamp electronics 110 areelectrically coupled to the Edison screw 103 such that the electricalconnection may be made from the Edison screw 103 to the lamp electronics110. The base 102 may be potted to physically and electrically isolateand protect the lamp electronics 110. The lamp electronics 110 include afirst contact pad 96 and a second contact pad 98 that allow the lampelectronics 110 to be electrically coupled to the LED assembly 130 inthe lamp as will hereinafter be described. Contact pads 96 and 98 may beformed on printed circuit board 107 which includes the power supply,including large capacitor and EMI components that are across the inputAC line along with the driver circuitry as described herein.

Any aspect or features of any of the embodiments described herein can beused with any feature or aspect of any other embodiments describedherein or integrated together or implemented separately in single ormultiple components. The steps described herein may be performed in anautomated assembly line having rotary tables or other conveyances formoving the components between assembly stations.

In some embodiments, the submount 129 of the LED assembly 130 maycomprise a lead frame made of an electrically conductive material suchas copper, copper alloy, aluminum, steel, gold, silver, alloys of suchmetals, thermally conductive plastic or the like. In other embodiments,the submount comprises a PCB such as a metal core PCB as shown in FIGS.19 and 20. In one embodiment, the exposed surfaces of the submount 129may be coated with silver or other reflective material to reflect lightinside of enclosure 112 during operation of the lamp. The submount maycomprise a series of anodes and cathodes arranged in pairs forconnection to the LEDs 127. In the illustrated embodiment 20 pairs ofanodes and cathodes are shown for an LED assembly having 20 LEDs 127;however, a greater or fewer number of anode/cathode pairs and LEDs maybe used. Moreover, more than one submount may be used to make a singleLED assembly 130. For example, two submounts 129 may be used to make anLED assembly 130 having twice the number of LEDs as a single lead frame.

Connectors or conductors such as traces connect the anode from one pairto the cathode of the adjacent pair to provide the electrical pathbetween the anode/cathode pairs during operation of the LED assembly130. In a lead frame structure tie bars are also typically provided tohold the first portion of the lead frame to the second portion of thelead frame and to maintain the structural integrity of the lead frameduring manufacture of the LED assembly 129. The tie bars are cut fromthe finished LED assembly and perform no function during operation ofthe LED assembly 130.

The submount 129 also comprises connector portion 153 that functions tocouple the LED assembly 130 to the heat sink 149 such that heat may bedissipated from the LED assembly; to mechanically couple the LEDassembly 130 to the heat sink 149; and to electrically couple the LEDassembly 130 to the electrical path. The submount 129 may have a varietyof shapes, sizes and configurations.

The lead frame may be formed by a stamping process and a plurality oflead frames may be formed in a single strip or sheet or the lead framesmay be formed independently. In one method, the lead frame is formed asa flat member and is bent into a suitable three-dimensional shape suchas a cylinder, sphere, polyhedra or the like to form LED assembly 130.Because the lead frame is made of thin bendable material, and the anodesand cathodes may be positioned on the lead frame in a wide variety oflocations, and the number of LEDs may vary, the lead frame may beconfigured such that it may be bent into a wide variety of shapes andconfigurations.

An LED or LED package containing at least one LED 127 is secured to eachanode and cathode pair where the LED/LED package spans the anode andcathode. The LEDs/LED packages may be attached to the submount bysoldering. In a lead frame arrangement once the LEDs/LED packages areattached, the tie bars may be removed because the LED packages hold thefirst portion of the lead frame to the second portion of the lead frame.

In some embodiments of a lead frame submount, separate stiffeners orsupports (not shown) may be provided to hold the lead frame together.The supports may comprise non-conductive material attached between theanode and cathode pairs to secure the lead frame together. The supportsmay comprise insert molded or injection molded plastic members that tiethe anodes and cathodes together. The lead frame may be provided withpierced areas that receive the supports to provide holds that may beengaged by the supports. For example, the areas may comprise throughholes that receive the plastic flow during a molding operation. Thesupports may also be molded or otherwise formed separately from the leadframe and attached to the lead frame in a separate assembly operationsuch as by using a snap-fit connection, adhesive, fasteners, a frictionfit, a mechanical connection or the like. The plastic material extendsthrough the pierced areas to both sides of the lead frame such that theplastic material bridges the components of the lead from to hold thecomponents of the lead frame together after the tie bars are cut. Thesupports on the outer side of the lead frame (the term “outer” as usedherein is the side of the lead frame to which the LEDs are attached)comprises a minimum amount of plastic material such that the outersurface of the lead frame is largely unobstructed by the plasticmaterial. The plastic material should avoid the mounting areas for theLEDs such that the LEDs have an unobstructed area at which the LEDs maybe attached to the lead frame. On the inner side of the lead frame (theterm “inner” as used herein is the side of the lead frame opposite theside to which the LEDs are attached) the application of the plasticmaterial may mirror the size and shape of the supports on the outerside; however, the supports on the inner side does need to be as limitedsuch that the supports may comprise larger plastic areas and a greaterarea of the lead frame may be covered. The plastic material extends overlarger areas of the inner side of the lead frame such that the plasticprovides structural support for the lead frame.

Further, a first plastic overhang is provided on a first lateral end ofthe lead frame and a second plastic overhang is provided on a secondlateral end of the lead frame. Because, in one embodiment the flat leadframe is bent to form a three-dimensional LED assembly, it may benecessary to electrically isolate the two ends of the lead frame fromone another in the assembled LED assembly where the two ends havedifferent potentials. The lead frame may be bent to form a cylindricalLED assembly where the lateral edges and of the lead frame are broughtin close proximity relative to one another. The plastic overhangs arearranged such that the two edges of the lead frame are physicallyseparated and electrically insulated from one another by the overhangs.The overhangs are provided along a portion of the two edges of the leadframe; however, the plastic insulating overhangs may extend over theentire free ends of the lead frame and the length and thickness of theoverhangs depends upon the amount of insulation required for theparticular application.

In addition to electrically insulating the edges of the lead frame, theplastic overhangs may be used to join the edges of the lead frametogether in the three dimensional LED assembly. One of the overhangs maybe provided with a first connector or connectors that mates with asecond connector or connectors provided on the second overhang. Thefirst connectors may comprise a male or female member and the secondconnectors may comprise a mating female or male member. Because theoverhangs are made of plastic the connectors may comprise deformablemembers that create a snap-fit connection. The flat lead frame may bebent to have the generally cylindrical configuration as shown where theside edges are brought into close proximity to one another. The matingconnectors formed on the first overhang and second overhang may beengaged with one another to hold the lead frame in the finalconfiguration.

In another embodiment of LED assembly 130 the submount 129 may comprisea metal core board such as a metal core printed circuit board (MCPCB) asshown, for example, in FIGS. 16, 19 and 20. The metal core boardcomprises a thermally and electrically conductive core made of aluminumor other similar pliable metal material. The core is covered by adielectric material such as polyimide. Metal core boards allow traces tobe formed therein. In one method, the core board is formed as a flatmember and is bent into a suitable shape such as a cylinder, sphere,polyhedra or the like. Because the core board is made of thin bendablematerial and the anodes and cathodes may be positioned in a wide varietyof locations, and the number of LED packages may vary, the metal coreboard may be configured such that it may be bent into a wide variety ofshapes and configurations.

In one embodiment the core board is formed as a flat member having afirst LED mounting portion 151 on which the LEDs/LED packages containingLEDs 127 are mounted. The first portion 151 may be divided into sectionsby thinned areas or score lines 151 a. The LEDs/LED packages are locatedon the sections such that the core board may be bent along the scorelines to form the planar core board into a variety of three-dimensionalshapes where the shape is selected to project a desired light patternfrom the lamp 100.

In another embodiment of the LED assembly 130 the submount 129 comprisesa hybrid of a metal core board and lead frame. The metal core boardforms the LED mounting portion 151 on which the LED packages containingLEDs 127 are mounted where the back side of the metal core board may bemechanically coupled to a lead frame structure. The lead frame structureforms the connector portion 153. Both the lead frame and the metal coreboard may be bent into the various configurations as discussed herein.The metal core board may be provided with score lines or reducedthickness areas to facilitate the bending of the core board. The LEDassembly may also comprise a PCB made with FR4 and thermal vias ratherthan the metal core board where the thermal vias are then connected tothe lead frame structure.

In another embodiment of LED assembly 130 the submount 129 may comprisean extruded submount which may be formed of aluminum or copper or othersimilar material. A flex circuit or board may be mounted on the extrudedsubmount that supports LEDs 127. The extruded submount may comprise avariety of shapes such as previously described.

The submount 129 may be bent or folded such that the LEDs 127 providethe desired light pattern in lamp 100. In one embodiment the submount129 is bent into a cylindrical shape as shown in the figures. The LEDs127 are disposed about the axis of the cylinder such that light isprojected outward. In a lead frame configuration, the lead frame may bebent at the connectors and in a metal core board configuration the coreboard may be bent at thinned score to form the three-dimensional LEDassembly 130. The LEDs 127 may be arranged around the perimeter of theLED assembly to project light radially.

Because the submount 129 is pliable and the LED placement on thesubstrate may be varied, the submount may be formed and bent into avariety of configurations. For example one of the LEDs 127 may be angledtoward the bottom of the LED assembly 130 and another of the LEDs 127may be angled toward the top of the LED assembly 130 with the remainingLEDs projecting light radially from a cylindrical LED assembly 130. LEDstypically project light over less than 180 degrees such that tiltingselected ones of the LEDs ensures that a portion of the light isprojected toward the bottom and top of the lamp. Some LEDs project lightthrough an angle of 120 degrees. By angling selected ones of the LEDsapproximately 30 degrees relative to the axis of the LED assembly 130the light projected from the cylindrical array will project light over360 degrees. The angles of the LEDs and the number of LEDs may be variedto create a desired light pattern. For example, the figures show anembodiment of a two tiered LED assembly 130 where each tier comprises aseries of a plurality of LEDs 127 arranged around the perimeter of thecylinder. While a two tiered LED assembly is shown the LED assembly maycomprise one tier, three tiers or additional tiers of LEDs where eachtier comprises a series of a plurality of LEDs 127 arranged around theperimeter of the cylinder. Selected ones of the LEDs may be angled withrespect to the LED array to project a portion of the light along theaxis of the cylindrical LED assembly toward the top and bottom of theLED assembly. The LED assembly may be shaped other than as a cylindersuch as a polyhedron, a helix or double helix with two series of LEDpackages each arranged in series to form a helix shape. In theillustrated embodiments the submount is formed to have a generallycylindrical shape; however, the substrate may have a generallytriangular cross-sectional shape, a hexagonal cross-sectional shape, orany polygonal shape or even more complex shapes.

The LED assembly 130, whether made of a lead frame submount, metal coreboard submount, a hybrid combination of metal core board/lead framesubmount, a PCB made with FR4/lead frame submount or an extrudedsubmount, may be formed to have any of the configurations shown anddescribed herein or other suitable three-dimensional geometric shape.The LED assembly 130 may be advantageously bent or formed into anysuitable three-dimensional shape. A “three-dimensional” LED assembly asused herein and as shown in the drawings means an LED assembly where thesubstrate comprises mounting surfaces for different ones of the LEDsthat are in different planes such that the LEDs mounted on thosemounting surfaces are also oriented in different planes. In someembodiments the planes are arranged such that the LEDs are disposed overa 360 degree range. The substrate may be bent from a flat configuration,where all of the LEDs are mounted in a single plane on a generallyplanar member, into a three-dimensional shape where different ones ofthe LEDs and LED mounting surfaces are in different planes.

As previously mentioned, the submount in a lamp according to embodimentsof the invention can optionally include the power supply or driver orsome components for the power supply or driver for the LED array. Insome embodiments, the LEDs can actually be powered by AC. Variousmethods and techniques can be used to increase the capacity and decreasethe size of a power supply in order to allow the power supply for an LEDlamp to be manufactured more cost-effectively, and/or to take up lessspace in order to be able to be built on a submount. For example,multiple LED chips used together can be configured to be powered with arelatively high voltage. Additionally, energy storage methods can beused in the driver design. For example, current from a current sourcecan be coupled in series with the LEDs, a current control circuit and acapacitor to provide energy storage. A voltage control circuit can alsobe used. A current source circuit can be used together with a currentlimiter circuit configured to limit a current through the LEDs to lessthan the current produced by the current source circuit. In the lattercase, the power supply can also include a rectifier circuit having aninput coupled to an input of the current source circuit.

Some embodiments of the invention can include a multiple LED setscoupled in series. The power supply in such an embodiment can include aplurality of current diversion circuits, respective ones of which arecoupled to respective nodes of the LED sets and configured to operateresponsive to bias state transitions of respective ones of the LED sets.In some embodiments, a first one of the current diversion circuits isconfigured to conduct current via a first one of the LED sets and isconfigured to be turned off responsive to current through a second oneof the LED sets. The first one of the current diversion circuits may beconfigured to conduct current responsive to a forward biasing of thefirst one of the LED sets and the second one of the current diversioncircuit may be configured to conduct current responsive to a forwardbiasing of the second one of the LED sets.

In some of the embodiments described immediately above, the first one ofthe current diversion circuits is configured to turn off in response toa voltage at a node. For example a resistor may be coupled in serieswith the sets and the first one of the current diversion circuits may beconfigured to turn off in response to a voltage at a terminal of theresistor. In some embodiments, for example, the first one of the currentdiversion circuits may include a bipolar transistor providing acontrollable current path between a node and a terminal of a powersupply, and current through the resistor may vary an emitter bias of thebipolar transistor. In some such embodiments, each of the currentdiversion circuits may include a transistor providing a controllablecurrent path between a node of the sets and a terminal of a power supplyand a turn-off circuit coupled to a node and to a control terminal ofthe transistor and configured to control the current path responsive toa control input. A current through one of the LED sets may provide thecontrol input. The transistor may include a bipolar transistor and theturn-off circuit may be configured to vary a base current of the bipolartransistor responsive to the control input.

With respect to the features described above with various exampleembodiments of a lamp, the features can be combined in various ways. Forexample, the various methods of including phosphor in the lamp can becombined and any of those methods can be combined with the use ofvarious types of LED arrangements such as bare die vs. encapsulated orpackaged LED devices. The embodiments shown herein are examples only,shown and described to be illustrative of various design options for alamp with an LED array.

LEDs and/or LED packages used with an embodiment of the invention andcan include light emitting diode chips that emit hues of light that,when mixed, are perceived in combination as white light. Phosphors canbe used as described to add yet other colors of light by wavelengthconversion. For example, blue or violet LEDs can be used in the LEDassembly of the lamp and the appropriate phosphor can be in any of theways mentioned above. LED devices can be used with phosphorized coatingspackaged locally with the LEDs or with a phosphor coating the LED die aspreviously described. For example, blue-shifted yellow (BSY) LEDdevices, which typically include a local phosphor, can be used with ared phosphor on or in the optically transmissive enclosure or innerenvelope to create substantially white light, or combined with redemitting LED devices in the array to create substantially white light.Such embodiments can produce light with a CRI of at least 70, at least80, at least 90, or at least 95. By use of the term substantially whitelight, one could be referring to a chromacity diagram including ablackbody 160 locus of points, where the point for the source fallswithin four, six or ten MacAdam ellipses of any point in the blackbody160 locus of points.

A lighting system using the combination of BSY and red LED devicesreferred to above to make substantially white light can be referred toas a BSY plus red or “BSY+R” system. In such a system, the LED devicesused include LEDs operable to emit light of two different colors. In oneexample embodiment, the LED devices include a group of LEDs, whereineach LED, if and when illuminated, emits light having dominantwavelength from 440 to 480 nm. The LED devices include another group ofLEDs, wherein each LED, if and when illuminated, emits light having adominant wavelength from 605 to 630 nm. A phosphor can be used that,when excited, emits light having a dominant wavelength from 560 to 580nm, so as to form a blue-shifted-yellow light with light from the formerLED devices. In another example embodiment, one group of LEDs emitslight having a dominant wavelength of from 435 to 490 nm and the othergroup emits light having a dominant wavelength of from 600 to 640 nm.The phosphor, when excited, emits light having a dominant wavelength offrom 540 to 585 nm. A further detailed example of using groups of LEDsemitting light of different wavelengths to produce substantially whilelight can be found in issued U.S. Pat. No. 7,213,940, which isincorporated herein by reference.

Referring again to the figures, the LED assembly 130 may be mounted tothe heat sink structure 149 by an electrical interconnect 150 where theelectrical interconnect 150 provides the electrical connection betweenthe LED assembly 130 and the lamp electronics 110. The heat sinkstructure 149 comprises a heat conducting portion or tower 152 and aheat dissipating portion 154 as shown for example in FIGS. 12 and 15. Inone embodiment the heat sink 149 is made as a one-piece member of athermally conductive material such as aluminum. The heat sink structure149 may also be made of multiple components secured together to form theheat structure. Moreover, the heat sink 149 may be made of any thermallyconductive material or combinations of thermally conductive materials.In some embodiments the heat conducting portion 152 may be made ofnon-thermally conducting material such as plastic or portion 152 may beeliminated completely. In these embodiments, the LED assembly 130 may bedirectly coupled to the heat dissipating portion 154 without the use ofa separate heat conducting portion. Extensions 190, as shown for examplein FIG. 16, may be formed on the LED assembly that connect the LEDassembly 130 to the heat dissipating portion 154 and that position andsupport the LEDs 127 in the proper position in the enclosure.

The heat conducting portion 152 is formed as a tower that is dimensionedand configured to make good thermal contact with the LED assembly 130such that heat generated by the LED assembly 130 may be efficientlytransferred to the heat sink 149. In one embodiment, the heat conductingportion 152 comprises a tower that extends along the longitudinal axisof the lamp and extends into the center of the enclosure. The heatconducting portion 152 may comprise generally cylindrical outer surfacethat matches the generally cylindrical internal surface of the LEDassembly 130. In the illustrated embodiment the portions of thesubstrate 129 on which the LEDs 127 are mounted are generally planar. Asa result, while the LED assembly 130 is generally cylindrical, thecylinder is comprised of a plurality of planar segments. In oneembodiment the heat conducting portion 152 is formed with a plurality ofplanar facets 156 that abut the planar portions of the submount 129 toprovide good surface to surface contact. While the LED assembly 130 andthe heat conducting portion 152 are shown as being cylindrical thesecomponents may have any configuration provided good thermal conductivityis created between the LED assembly 130 and the heat conducting portion152. As previously explained, the LED assembly 130 may be formed in awide variety of shapes such that the heat conducting portion 152 may beformed in a corresponding mating shape. Further, while heat transfer maybe most efficiently made by forming the heat conducting portion 152 andthe LED assembly 130 with mating complimentary shapes, the shapes ofthese components may be different provided that sufficient heat isconducted away from the LED assembly 130 that the operation and/or lifeexpectancy of the LEDs are not adversely affected.

The heat dissipating portion 154 is in good thermal contact with theheat conducting portion 152 such that heat conducted away from the LEDassembly 130 by the heat conducting portion 152 may be efficientlydissipated from the lamp 100 by the heat dissipating portion 154. In oneembodiment the heat conducting portion 152 and heat dissipating portion154 are formed as one-piece. The heat dissipating portion 154 extendsfrom the interior of the enclosure 112 to the exterior of the lamp 100such that heat may be dissipated from the lamp to the ambientenvironment. In one embodiment the heat dissipating portion 154 isformed generally as a disk where the distal edge of the heat dissipatingportion 154 extends outside of the lamp and forms an annular ring thatsits on top of the open end of the base 102. A plurality of heatdissipating members 158 may be formed on the exposed portion tofacilitate the heat transfer to the ambient environment. In oneembodiment, the heat dissipating members 158 comprise a plurality finsthat extend outwardly to increase the surface area of the heatdissipating portion 154. The heat dissipating portion 154 and fins 158may have any suitable shape and configuration.

Different embodiments of the LED assembly and heat sink tower arepossible. In various embodiments, the LED assembly may be relativelyshorter, longer, wider or thinner than that shown in the illustratedembodiment. Moreover the LED assembly may engage the heat sink andelectronics in a variety of manners. For example, the heat sink may onlycomprise the heat dissipating portion 154 and the heat conductingportion or tower 152 may be integrated with the LED assembly 130 suchthat the integrated heat sink portion and LED assembly engage the heatdissipating portion 154 at its base. In other embodiments, the LEDassembly 130 may engage the heat conducting portion 152 of the heat sink149 where the LED assembly does not include the connector portion 153.In some embodiments, the LED assembly and heat sink may be integratedinto a single piece or be multiple pieces other than as specificallydefined.

The electrical interconnect 150 provides the electrical conductors toconnect the LED assembly 130 to the lamp electronics 110 and is shown inFIGS. 13, 14, 17 and 18. An inventive aspect of the LED lamp involvesthe interconnect 150 which provides improved manufacturability byproviding an electrical connection between the LED assembly 130 and thedrive electronics that does not require bonding of the contacts from thedrive electronics to the LED assembly. In other embodiments, anelectrical interconnect according to aspects of the present inventioncan be used to connect the AC line to the drive electronics or fromportions of the power supply to other portions of the drive electronicsdepending on the embodiment and the positioning of the drive electronicson the LED assembly.

In some embodiments, the electrical interconnect includes a supportand/or alignment arrangement or element which can be integral with orseparate from the contacts. The support and/or alignment arrangement isconfigured to position the first and/or second set of contacts relativeto the corresponding electrical contacts of the LED assembly with powersupply, AC line or drive electronics depending on the embodiment. Theelectrical interconnect enables this connection to be made in an easyfashion to improve manufacturability by reducing the need for solderingof the electrical contacts. The electrical contacts of the interconnectcan be configured to engage the corresponding electrical contacts invarious ways to maintain a robust electrical connection in easierfashion. Such engagement can take various forms as would be understoodby one of ordinary skill in the art with the benefit of this disclosure.As shown in the figures, the electrical interconnect 150 comprises abody 160 that includes a first conductor 162 for connecting to one ofthe anode or cathode side of the LED assembly 130 and a second conductor164 for connecting to the other one of the anode or cathode side of theLED assembly 130. The first conductor 162 extends through the body 160to form an LED-side contact 162 a and a lamp electronics-side contact162 b. The second conductor 164 extends through the body 160 to form anLED-side contact 164 a and a lamp electronics-side contact 164 b. Thebody 160 may be formed by insert molding the conductors 162, 164 in aplastic insulator body 160. While the electrical interconnect 150 may bemade by insert molding the body 160, the electrical interconnect 150 maybe constructed in a variety of manners. For example, the body 160 may bemade of two sections that are joined together to trap the conductors162, 164 between the two body sections. Further, each conductor may bemade of more than one component provided an electrical pathway isprovided in the body 160.

A support and/or alignment mechanism is configured to position the firstand/or second set of contacts relative to the corresponding electricalcontacts of the LED assembly and power supply. The support and/oralignment mechanism may comprise a first engagement member 166 on body160 that engages a mating second engagement member 168 on the heat sink149. In one embodiment the first engagement member 166 comprises adeformable resilient finger that comprises a camming surface 170 and alock member 172. The second engagement member 168 comprises a fixedmember located in the internal cavity 174 of the heat sink 149. Theelectrical interconnect 150 may be inserted into the cavity 174 from thebottom of the heat sink 149 and moved toward the opposite end of theheat sink such that the camming surface 170 contacts the fixed member168. The engagement of the camming surface 170 with the fixed member 168deforms the finger 166 to allow the lock member 172 to move past thefixed member 168. As the lock member 172 passes the fixed member 168 thefinger 166 returns toward its undeformed state such that the lock member172 is disposed behind the fixed member 168. The engagement of the lockmember 172 with the fixed member 168 fixes the electrical interconnect150 in position in the heat sink 149. The snap-fit connection allows theelectrical interconnect 150 to be inserted into and fixed in the heatsink 149 in a simple insertion operation without the need for anyadditional connection mechanisms, tools or assembly steps. While oneembodiment of the snap-fit connection is shown, numerous changes may bemade. For example, the deformable resilient member may be formed on theheat sink 149 and the fixed member 168 may be formed on the electricalinterconnect 150. Moreover, both the first and the second engagementmembers may be deformable and more than one of each engagement membermay be used. Further, rather than using a snap-fit connection, theelectrical interconnect 150 may be fixed to the heat sink using otherconnection mechanisms such as a bayonet connection, screwthreads,friction fit or the like that also do not require additional connectionmechanisms, tools or assembly steps.

The support and/or alignment arrangement may properly orient theelectrical interconnect 150 in the heat sink 149 and provide a passagefor the LED-side contacts 162 a, 164 a, and may comprise a first slot176 and a second slot 178 formed in the heat conducting portion 152. Thefirst slot 176 and the second slot 178 may be arranged opposite to oneanother and receive ears or tabs 180 that extend from the body 160. Thetabs 180 are positioned in the slots 176, 178 such that as theelectrical interconnect 150 is inserted into the heat sink 149, the tabs180 engage the slots 176, 178 to guide the electrical interconnect 150into the heat sink 149. The tabs 180 and slots 176, 178 may be formedwith mating trapezoidal shapes such that as the tabs 180 are insertedinto the slots 176, 178 the mating narrowing sides properly align theelectrical interconnect 150 in the heat sink 149.

The first LED-side contact 162 a and the second LED-side contact 164 aare arranged such that the contacts extend through the first and secondslots 176, 178, respectively, as the electrical interconnect 150 isinserted into the heat sink 149. The contacts 162 a, 164 a are exposedon the outside of the heat conducting portion 152. The contacts 162 a,164 a are arranged such that they create an electrical connection to theanode side and the cathode side of the LED assembly 130 when the LEDassembly 130 is mounted on the heat sink 149. In the illustratedembodiment the contacts are identical such that specific reference willbe made to contact 164 a. The contact 164 a comprises a laterallyextending portion 182 that extends from the body 160 and that extendsthrough the slot 178. The laterally extending portion 182 connects to aspring portion 182 that is arranged such that it extends over the heatconducting portion 152 and abuts or is in close proximity to the outersurface of the heat conducting portion 152. The contact 164 a isresilient such that it can be deformed to ensure a good electricalcontact with the LED assembly 130 as will be described.

The first electronic-side contact 162 b and the second electronic-sidecontact 164 b are arranged such that the contacts 162 b, 164 b extendbeyond the bottom of the heat sink 149 when the electrical interconnect150 is inserted into the heat sink 149. The contacts 162 b, 164 b arearranged such that they create an electrical connection to the anodeside and the cathode side of the lamp electronics 110. In theillustrated embodiment the contacts 162 b, 164 b are identical such thatspecific reference will be made to contact 164 b. The contact 164 bcomprises a spring portion 184 that is arranged such that it extendsgenerally away from the electrical interconnect 150. The contact 164 bis resilient such that it can be deformed to ensure a good electricalcontact with the lamp electronics 110 as will be described.

To mount the LED assembly 130 on the heat sink 149 the heat conductingportion 152 of heat sink 149 is inserted into the LED assembly 130 suchthat the LED assembly 130 surrounds and contacts the heat conductingportion 152. The LED assembly 130 comprises an anode side contact 186and a cathode side contact 188. The contacts 186, 188 may be formed aspart of the conductive submount 129 on which the LEDs are mounted. Forexample, the contacts 186, 188 may be formed as part of the PCB, leadframe or metal circuit board or other submount 129. The contacts 186,188 are electrically coupled to the LEDs 127 such that they form part ofthe electrical path between the lamp electronics 110 and the LEDassembly 130. The contacts 186, 188 extend from the LED mounting portion151 such that when the LED assembly 130 is mounted on the heat sink 149the contacts 186, 188 are disposed between the LED-side contacts 162 a,164 a, respectively, and the heat sink 149. The LED-side contacts 162 a,164 a are arranged such that as the contacts 186, 188 are insertedbehind the LED-side contacts 162 a, 164 a, the LED-side contacts 162 a,164 a are slightly deformed. Because the LED-side contacts 162 a, 164 aare resilient, a bias force is created that biases the LED-side contacts162 a, 164 a into engagement with the LED assembly 130 contacts 186, 188to ensure a good electrical coupling between the LED-side contacts 162a, 164 a and the LED assembly 130. The engagement between the LED-sidecontacts of the electrical interconnect 150 and the and the anode sidecontact and the cathode side contact of the LED assembly 130 is referredto herein as a contact coupling where the electrical coupling is createdby the contact under pressure between the contacts as distinguished froma soldered coupling.

To position the LED assembly 130 relative to the heat sink and to fixthe LED assembly 130 to the heat sink, a pair of extensions 190 areprovided on the LED assembly 130 that engage mating receptacles 192formed on the heat sink. In one embodiment the extensions 190 compriseportions of the submount 129 that extend away from the LED mounting area151 of the LED assembly 130. The extensions 190 extend toward the bottomof the heat sink 149 along the direction of insertion of the LEDassembly 130 onto the heat sink. The heat sink 149 is formed with matingreceptacles 192 that are dimensioned and arranged such that one of theextensions 190 is inserted into each of the receptacles 192 when theheat sink 149 is inserted into the LED assembly 130. The engagement ofthe extensions 190 and the receptacles 192 properly positions the LEDassembly 130 relative to the heat sink during assembly of the lamp.

Moreover, to fix the LED assembly 130 on the heat sink 149 and to seatthe LED assembly 130 against the heat conducting portion 152 to ensuregood thermal conductivity between these elements, the extensions 190 areformed with camming surfaces 194 that engage the receptacles 192 andclamp the LED assembly 130 on the heat sink 149. As explainedpreviously, in some embodiments the LED assembly 130 is formed of asubmount 129 that is formed as a planar member (see FIGS. 19 and 20) andis then bent or formed into the final shape of the LED assembly 130. Itwill be appreciated that as the submount is formed into thethree-dimensional shape, free ends of the submount 129 may be broughtinto close proximity to one another. For example, referring to FIG. 19,when the planar submount is bent into the three-dimensional cylindricalshape of FIG. 16, the free ends 129 a, 129 b of the submount 129 arebrought closely adjacent to one another. In the mounting system of theinvention, the engagement of the extensions 190 with the receptacles 192is used to hold the LED assembly 130 in the desired shape and to clampthe LED assembly 130 on the heat sink. As shown in FIGS. 16 and 19, asurface of each of the extensions 190 is formed as a camming surface 194where the camming surface 194 is created by arranging the surface 194 anangle relative to the insertion direction of the LED assembly 130 on theheat sink 149, or as a stepped surface, or as a curved surface or as acombination of such surfaces. As a result, as each extension 190 isinserted into the corresponding receptacle 192 the wall of thereceptacle 192 engages the camming surface 194 and, due to the angle orshape of the camming surface 194, exerts a force on the LED assembly 130tending to move one free end 129 a of the LED assembly 130 toward theopposite free end 129 b of the LED assembly 130. The extensions 190 areformed at or near the free ends of the LED assembly 130 and the cammingsurfaces 194 are arranged such that the free ends 129 a, 129 b of theLED assembly 130 are moved in opposite directions toward one another. Asthe free ends of the LED assembly 130 are moved toward one another, theinner circumference of the LED assembly 130 is gradually reduced suchthat the LED assembly 130 exerts an increasing clamping force on theheat conducting portion 152 as the LED assembly 130 is inserted on theheat sink 149. The camming surfaces 194 are arranged such that when theLED assembly 130 is completely seated on the heat sink 149 the LEDassembly 130 exerts a tight clamping force on the heat conductingportion 152. The clamping force holds the LED assembly 130 on the heatsink 149 and ensures a tight surface-to-surface engagement between theLED assembly 130 and the heat sink 149 such that heat generated by theLED assembly 130 is efficiently transferred to the heat sink 149. Theextensions 190 may be provided with a stop such as shoulder 195 thatabuts the edge of the receptacles 192 to limit the insertion of theextensions 190 into the receptacles 192. The LED assembly 130 is held onthe heat sink by the wedging action of the extensions 190 in thereceptacles 192 as well as the clamping force exerted by the LEDassembly 130 on the heat conducting portion 152. While a specificarrangement of the camming surfaces 194 and receptacles 192 is shown,the camming surfaces 194 may be formed on either or both of the heatsink 149 and LED assembly 130. The camming surfaces and the surfacesthat are engaged by the camming surfaces may have a variety ofstructures and forms. Moreover, one free end of the substrate may beheld stationary while the opposite end is moved toward the stationaryend. While a generally cylindrical heat conducting portion 152 and LEDassembly 130 are shown, these components may have a variety of shapesand sizes. The camming surfaces 194 may be arranged such that the LEDassembly 130 is moved in a wide variety of planes and directions suchthat various surfaces of the LED assembly 130 may be brought intoengagement with various surfaces of the heat sink 149.

When the electrical interconnect 150 is mounted to the heat sink 149 andthe LED assembly 130 is mounted on the heat sink 149, an electrical pathis created between the electronics-side contacts 162 a, 164 a of theelectrical interconnect 150 and the LED assembly 130. These componentsare physically and electrically connected to one another and theelectrical path is created without using any additional fasteners,connection devices, tools or additional assembly steps. The electricalinterconnect 150 is simply inserted into the heat sink 149 and the heatsink 149 is simply inserted into the LED assembly 130.

Once the heat sink/LED assembly subcomponent is completed, thesubcomponent may be attached to the base 102 as a unit. First engagementmembers on the base 102 may engage mating second engagement members onthe heat sink structure 149. In one embodiment, the first engagementmembers comprise deformable resilient fingers 101 that comprise acamming surface 107 and a lock member 109. The second engagement membercomprises apertures 111 formed in the heat sink 149 that are dimensionedto receive the fingers 101. In one embodiment, the housing 105 of thebase 102 is provided with fingers 101 that extend from the base 102toward the subcomponent. In the illustrated embodiment three fingers 101are provided although a greater or fewer number of fingers may beprovided. The fingers 101 may be made as one-piece with the housing 105.For example, the housing 105 and fingers 101 may be molded of plastic.The apertures 111 define fixed members 113 that may be engaged by thelock members 109 to lock the fingers 101 to the heat sink 149. The base102 may be moved toward the bottom of the heat sink 149 such thatfingers 101 are inserted into apertures 111 and the camming surfaces 107of the fingers 101 contact the fixed members 113. The engagement of thefixed members 113 with the camming surfaces 107 deforms the fingers 101to allow the locking members 109 to move past the fixed members 113. Asthe lock members 109 pass the fixed members 113 the fingers 101 returntoward their undeformed state such that the lock members 109 aredisposed behind the fixed members 113. The engagement of the lockmembers 109 with the fixed members 113 fixes the base 102 to the heatsink 149. The snap-fit connection allows the base 102 to be fixed to theheat sink 149 in a simple insertion operation without the need for anyadditional connection mechanisms, tools or assembly steps. While oneembodiment of the snap-fit connection is shown numerous changes may bemade. For example, the deformable members such as fingers may be formedon the heat sink 149 and the fixed members such as apertures may beformed on the base 102. Moreover, both engagement members may bedeformable. Further, rather than using a snap-fit connection, theelectrical interconnect 150 may be fixed to the heat sink using otherconnection mechanisms such as a bayonet connection, screwthreads,friction fit or the like. The fixed members 113 may be recessed belowthe upper surface of the heat dissipation portion 154 such that when thelock members 109 are engaged with the fixed members 113 the fingers 101do not extend above the plane of the upper surface 154 a of the heatdissipating portion 154 as best shown in FIG. 11.

As the base 102 is brought into engagement with the heat sink 149,electronic-side contacts 162 b, 164 b are inserted into the base 102.The lamp electronics 110 are provided with contact pads 96, 98 that arearranged such that when the base 102 is assembled to the heat sink 149,the electronic-side contacts 162 b, 164 b are in electrical contact withthe pads 96, 98 to complete the electrical path between the base 102 andthe LED assembly 130. The pads 96, 98 are disposed such that theelectronic-side contacts 162 b, 164 b are deformed slightly such thatthe resiliency of the contacts exerts a biasing force that presses thecontacts into engagement with the pads to ensure a good electricalconnection. The electronic-side contacts 162 b, 164 b may be formed withangled distal ends 191 that act as camming surfaces to deform thecontacts during assembly of the base to the heat sink. The cammingsurfaces may be arranged to contact a surface in the base, such as thePCB board 80, to deform the contacts upon insertion. The engagementbetween the electronics-side contacts of the electrical interconnect 150and the pads on the lamp electronics is referred to herein as a contactcoupling where the electrical coupling is created by the contact underpressure between the contacts and the pads as distinguished from asoldered coupling

The enclosure 112 may be attached to the heat sink 149. In oneembodiment, the LED assembly 130 and the heat conducting portion 152 areinserted into the enclosure 112 through the neck 115. The neck 115 andheat sink dissipation portion 154 are dimensioned and configured suchthat the rim of the enclosure 112 sits on the upper surface 154 a of theheat dissipation portion 154 with the heat dissipation portion 154disposed at least partially outside of the enclosure 112, between theenclosure 112 and the base 102. To secure these components together abead of adhesive may be applied to the upper surface 154 a of the heatdissipation portion 154. The rim of the enclosure 112 may be broughtinto contact with the bead of adhesive to secure the enclosure 112 tothe heat sink 149 and complete the lamp assembly. In addition tosecuring the enclosure 112 to the heat sink 149 the adhesive isdeposited over the snap-fit connection formed by fingers 101 andapertures 111. The adhesive flows into the snap fit connection topermanently secure the heat sink to the base.

In the illustrated embodiment, the electrical interconnect 150 is usedto secure the electrical conductors 162, 164 in the heat sink 149 and tomake the electrical connection between the LED assembly 130 and theconductors to thereby complete the electrical path between the LEDassembly 130 and the lamp electronics 110. In other embodiments, theelectrical interconnect 150 may also be used to effectuate themechanical connection between the heat sink 149 and the base 102. Forexample, as shown in FIG. 17, engagement members 90, 91 may extend fromthe bottom of the body 160 of the electrical interconnect 150 toward thebase 102. The engagement members 90, 91 may take the form of theresilient fingers as previously described. Mating engagement members onthe base 102, such as receptacles having a fixed member formed onhousing 105 (not shown), may be engaged by the engagement members 90, 91to provide a snap-fit connection between the base 102 and the heatsink/LED assembly subcomponent. In such an arrangement the electricalinterconnect 150 functions to complete the electrical path between theLED assembly 130 and the base 102 and to provide the mechanicalconnection between the base 102 and the heat sink/LED assemblysubcomponent.

In other embodiments, the electrical interconnect 150 may also be usedto effectuate the mechanical connection between the LED assembly 130 andthe heat sink 149. For example, as shown in FIG. 18, the electricalinterconnect 150 may be provided with secondary engagement members 86,88 that engage mating engagement members on the LED assembly 130. Thesecondary engagement members 86, 88 may take the form of the resilientfingers as previously described. The secondary engagement members 86, 88may engage the submount 129 directly such as by engaging the top edge ofthe submount. Alternatively, the LED assembly 130 may be provided withmating engagement members. For example, fixed members having engagementsurfaces may be molded or otherwise formed on the submount 129 such asduring the molding of the supports as previously described. In such anembodiment the electrical interconnect 150 functions to form themechanical connection between the LED assembly 130 and the heat sink149.

It is to be understood that the electrical interconnect 150 may be usedto provide one or all of the functions described herein. Moreover, theelectrical interconnect 150 may be used to provide various combinationsof the functions described herein.

In some embodiments the form factor of the lamp is configured to fitwithin the existing standard for a lamp such as the A19 ANSI standard.Moreover, in some embodiments the size, shape and form of the LED lampmay be similar to the size, shape and form of traditional incandescentbulbs. Users have become accustomed to incandescent bulbs havingparticular shapes and sizes such that lamps that do not conform totraditional forms may not be as commercially acceptable. The LED lamp ofthe invention is designed to provide desired performance characteristicswhile having the size, shape and form of a traditional incandescentbulb.

In the lamp of the invention, the LEDs 127 are arranged at or near theoptical center of the enclosure 112 in order to efficiently transmit thelumen output of the LED assembly through the enclosure 112. The mostefficient transmission of light through a transparent or semitransparentsurface is when the light incident to the surface is normal to thesurface. For example, if the enclosure is a perfect sphere, anomnidirectional light source located at the center of the sphereprovides the most efficient transmission of light through the enclosurebecause the light is normal to the surface of the enclosure at allpoints on the sphere's surface. In the lamp of the invention the LEDs127 are arranged at or near the optical center of the enclosure 112 tomaximize the amount of light that is normal to the surface of enclosure112. While all of the light emitted from LEDs 127 is not normal to theenclosure 112, with the LED assembly positioned at or near the opticalcenter of the enclosure more of the light is normal to the enclosurethan in solid state lamps where the light source is located near thebase of the enclosure or is otherwise located such that a large portionof the light is incident on the enclosure at other than right angles. Byfacing the LEDs 127 outwardly, the LEDs emit light in a generallyhemispherical pattern that maximizes the amount of light that is normalto the enclosure 112. Thus, the arrangement of the outwardly facing LEDsat or near the optical center of the enclosure, as shown in the figures,provides efficient transmission of the light through the enclosure 112to increase the overall efficiency of the lamp.

A second mechanism used in the lamp of the invention to increase theoverall efficiency of the lamp is the use of a boost converter topologypower supply to minimize losses and maximize conversion efficiency.Examples of boost topologies are described in U.S. patent applicationSer. No. 13/462,388, entitled “Driver Circuits for Dimmable Solid StateLighting Apparatus”, filed on May 2, 2012 which is incorporated byreference herein in its entirety; and U.S. patent application Ser. No.13/662,618, entitled “Driving Circuits for Solid-State LightingApparatus with High Voltage LED Components and Related Methods”, filedon Oct. 29, 2012 which is incorporated by reference herein in itsentirety. With boost technology there is a relatively small power losswhen converting from AC to DC. For example, boost technology may beapproximately 92% efficient while other power converting technology,such as Bud technology, may be approximately 85% efficient. Using a lessefficient conversion technology decreases the efficiency of the systemsuch that significant losses occur in the form of heat. The increase inheat must be dissipated from the lamp because heat adversely affects theperformance characteristics of the LEDs. The increase in efficiencyusing boost technology maximizes power to the LEDs while minimizing heatgenerated as loss. As a result, use of boost topology, or other highlyefficient topology, provides an increase in the overall efficiency ofthe lamp and a decrease in the heat generated by the power supply.

In one embodiment of the invention as shown and described herein, 20LEDs are provided where each LED comprises four LED chips. Each chip maybe a 3 volt LED chip such that each LED is a 12 volt part. Using 20 LEDsprovides an LED assembly of approximately 240 volts. Such an arrangementprovides a lamp having an output comparable to a 60 Watt incandescentbulb. The use of 20 LEDs each comprising 4 LED chips provides a LEDlight source having a relatively large epitaxial (EPI) or lightproducing area where each LED may be operated at relatively low current.In one embodiment described herein each LED chip may comprise a DA600chip sold by CREE Inc., where each chip is a square 600 micron chiphaving an EPI area of approximately 0.36 mm² such that each LED having 4LED chips has approximately 1.44 mm² of EPI area. A system such asdescribed herein with 20 LEDs has approximately 28.8 mm² of EPI area.

Generally speaking, in a typical LED the greater the operating currentof the LEDs the higher the lumen output of the LED. As a result, in atypical LED lamp the LEDs are operated in the area of about 350 mA/(mm²of EPI area) in order to maximize the lumen output per square mm of EPIarea. While operating the LEDs at high current increases the lumenoutput it also decreases the efficiency (lumens per watt) of the LEDssuch that significant losses occur in the form of heat. For example, theefficiency of one typical LED is greatest in the 60-90 mA/(mm² of EPIarea) and gradually decreases as the mA/(mm² of EPI area) increases. Theincrease in heat due to the lowering of efficiency must then bedissipated from the lamp because heat adversely affects the performancecharacteristics of the LEDs. The present invention uses the generallyinverse relationship between efficiency and lumen output to providelumen output at a desired level in a more efficient (i.e. less heat lossper lumen) lamp. While the relationship between efficiency and lumenoutput is described as generally inverse it is noted that efficiencyalso decreases at low current per unit area of EPI such that decreasingcurrent below the high efficiency range provides an LED that is bothless efficient and produces fewer lumens per unit area of EPI. Thus, itis desired to operate the LEDs in the area of greatest efficiency whileproviding a desired lumen output using a relatively large EPI area. Thelarge EPI area may be provided using a plurality of LEDs that togetherprovide the desired large EPI area.

Using a large EPI area LED assembly operating at a relatively lowcurrent decreases the lumen output per unit of EPI area but increasesthe efficiency of the LEDs such that less heat is generated per lumenoutput. The lower lumen output per unit of EPI area is offset by using alarger EPI area such that the lumen output of the lamp is increased perunit of heat generated by the system. In one embodiment, an LED assemblyhaving approximately 28.8 mm² of EPI area is used where the LEDs areoperated at approximately 107 mA/(mm² of EPI area) to provide theequivalent lumens as a 60 Watt incandescent light bulb. To provide theequivalent lumens as a 60 Watt incandescent light bulb an LED assemblyhaving an EPI area of between 15 and 40 mm² may be used where the LEDsare operated in the range of 200 and 75 mA/(mm² of EPI area). The largerthe EPI area the smaller the operating current such that an LED assemblyhaving 40 mm² of EPI area is operated at 75 mA/(mm² of EPI area) and aLED assembly having 15 mm² of EPI area is operated at 200 mA/(mm² of EPIarea). Other operating parameters for an LED assembly for a 60 wattequivalent lamp are 10 mm² of EPI area operated at 300 mA/(mm² of EPIarea) and a LED assembly having 20 mm² of EPI area operated at 150mA/(mm² of EPI area). For lamps having lumen output equivalent to otherthan a 60 watt bulb, such as a 40 watt bulb or a 100 watt bulb thesevalues may be scaled accordingly. While the scaling is not strictlylinear the scaling up or down in equivalent wattage is approximatelylinear. The term large EPI area as used herein means a light producingarea of sufficient size to produce the desired lumen output when theLEDs are operated at a current at or near the highest efficiency area onthe amperage to lumen per Watt curve for the LED. The desired lumenoutput can be achieved by increasing and/or decreasing current to theLEDs while simultaneously decreasing and/or increasing the EPI area. Therelationship between these variables depends on the amount of heat thatmay be adequately dissipated from the lamp using a relatively small heatsink and the amount of EPI area (e.g. the number of LEDs) that may besupported in the lamp. The size of the heat sink is selected such thatthe heat sink does not affect the outward design of the lamp such thatthe lamp has the same general size, shape and appearance as atraditional incandescent bulb. The size of the EPI area and the mA perunit of EPI area may then be selected to generate heat that is less thanthe amount of heat that can be adequately dissipated by the heat sink.

As a result, the lamp of the invention generates the desired lumenoutput while generating significantly less heat than in existing lampsby using the LEDs located at the optical center of the enclosure, boostconversion technology and efficient EPI area to mA/(mm² of EPI area) asdescribed above. Because of the efficiencies engineered into the lamp,the heat generated by the system is lower compared to existing LED lampsof similar lumen output such that a relatively small heat sink may beused. Because the heat sink may be made smaller than in known LED lampsthe form factor of the lamp may follow the form factor of traditionalincandescent bulbs. In one embodiment, the lamp 100 is configured to bea replacement for an ANSI standard A19 bulb such that the dimensions ofthe lamp 100 fall within the ANSI standards for an A19 bulb. Thedimensions may be different for other ANSI standards including, but notlimited to, A21 and A23 standards. In some embodiments, the LED lamp 100may be equivalent to standard watt incandescent light bulbs such as, butnot limited to, 40 Watt or 60 Watt bulbs. The use of a smaller heat sinkallows greater freedom in the design of the physical shape, size andconfiguration of the lamp such that the lamp may be configured to have avariety of shapes and sizes. Referring to FIG. 1 for example, the heatsink intrudes to a minimal degree on the external form of the lamp suchthat the lamp may be designed and configured to closely match the sizeand shape of a standard incandescent bulb such as an A19 bulb. Moreover,because a relatively small heat sink may be used it may be possible toprovide sufficient heat dissipation using a thermally conductive base102 without the intervening heat sink structure 154. In some embodimentsof an equivalent 60 watt and 75 watt lamp (total bulb power between 9and 11 watts), a heat sink having an exposed surface area in the rangeof range of approximately 20-40 square centimeters is sufficient and maybe considered small. In one embodiment for a 60 watt lamp the heat sinkmay have an exposed surface area of about 30 square centimeters. For 100W applications (or 75 W applications where higher optical losses areincurred such as in directional lamps with a total bulb power greaterthan 11 watts but less than 17 watts) the exposed surface area of theheat sink is in the range of range of approximately 40-80 squarecentimeters. In one embodiment for a 100 watt lamp the heat sink mayhave an exposed surface area of about 60 square centimeters.

LEDs are thermally responsive light producers where, as the LED getshotter, the lumens produced by the LED decreases. Because the lamp ofthe invention uses a relatively large EPI area to more efficientlygenerate large lumen outputs, the size of the heat sink may be reducedsuch that the loss of lumen output due to the heating of the LEDs may bedesigned into the system. In such an arrangement, the LEDs are notcooled to the extent required in existing devices and the heat sink maybe correspondingly reduced in size. For example, in one of the mostefficient types of commercially available lamps, a troffer lamp, thelarge heat sink allows the LEDs to operate at about a 4% loss of lumensdue to heat. In a typical bulb configuration the loss of lumens due toheat is engineered to be as small as possible and may be on the order ofless than 10%. In order to provide such a low “roll off” or loss oflumens due to heat build-up the typical LED lamp requires a relativelylarge heat sink structure. The lamp of the invention is designed suchthat the roll off or loss of lumens due to heat build-up may be betweenapproximately 15% and 20%. Such a loss would normally be consideredexcessive; however, because of the use of a large EPI area and the otherefficiencies built into the system as discussed above, the LED lamp ofthe invention can afford a larger lumen roll off at the LEDs and stillprovide a lamp that provides the desired lumen output at the systemlevel. In the system of the invention the LEDs are operated at ajunction temperature (the temperature at the junction between the LEDchip and the package) of between approximately 110° and 120°. Becausethe LEDs are allowed to operate at a relatively high junctiontemperature the heat sink may be made smaller and less intrusive whencompared to existing LED lamps. As explained above, the ability to use asmaller heat sink structure allows the heat sink to be a smaller andless obtrusive component of the overall lamp allowing the lamp to beconfigured to be of similar size and shape to a standard incandescentbulb as shown in the figures.

FIGS. 21-26 show an embodiment of a lamp that uses the LED assembly 130,heat sink with the tower arrangement 149, and electrical interconnect150 as previously described in a BR and PAR type lamp. The previousembodiments of a lamp refer more specifically to an omnidirectional lampsuch as an A19 replacement bulb. In the BR or PAR lamp shown in FIG. 21the light is emitted in a directional pattern rather than in anomnidirectional pattern. Standard BR type bulbs are reflector bulbs thatreflect light in a directional pattern; however, the beam angle is nottightly controlled and may be up to about 90-100 degrees or other fairlywide angles. The bulb shown in FIGS. 21-26 may be used as a solid statereplacement for such BR, PAR or reflector type bulbs or other similarbulbs.

The lamp comprises a base 102, heat sink 149, LED assembly 130 andelectrical interconnect 150 as previously described. As previouslyexplained, the LED assembly 130 generates an omnidirectional lightpattern. To create a directional light pattern, a primary reflector 300is provided that reflects light generated by the LED assembly 130generally in a direction along the axis of the lamp. Because the lamp isintended to be used as a replacement for a BR type lamp the reflector300 may reflect the light in a generally wide beam angle and may have abeam angle of up to approximately 90-100 degrees. As a result, thereflector 300 may comprise a variety of shapes and sizes provided thatlight reflecting off of the reflector 300 is reflected generally alongthe axis of the lamp. The reflector 300 may, for example, be conical,parabolic, hemispherical, faceted or the like. In some embodiments, thereflector may be a diffuse or Lambertian reflector and may be made of awhite highly reflective material such as injection molded plastic, whiteoptics, PET, MCPET, or other reflective materials. The reflector mayreflect light but also allow some light to pass through it. Thereflector 300 may be made of a specular material. The specularreflectors may be injection molded plastic or die cast metal (aluminum,zinc, magnesium) with a specular coating. Such coatings could be appliedvia vacuum metallization or sputtering, and could be aluminum or silver.The specular material could also be a formed film, such as 3M's VikuitiESR (Enhanced Specular Reflector) film. It could also be formedaluminum, or a flower petal arrangement in aluminum using Alanod's Miroor Miro Silver sheet.

The reflector 300 is mounted in the lamp such that it surrounds the LEDassembly 130 and reflects some of the light generated by the LEDassembly. In some embodiments, the reflector 300 reflects at least 20%of the light generated by the LED assembly. In other embodiments, thereflector 300 reflects about at least 40% of the light generated by theLED assembly 130 and in other embodiments, the reflector 300 may reflectabout at least 60% of the light generated by the LED assembly 130.Because the reflector 300 may be at least 95% reflective, the more lightthat hits the reflector 300 the more efficient the lamp. This is incontrast to the reflective aluminum coating typically found on astandard BR lamp enclosure that is approximately 80% reflective.

The reflector 300 may be mounted on the heat sink 149 or LED assembly130 using a variety of connection mechanisms. In one embodiment, thereflector 300 is mounted on the heat conducting portion or tower 152 ofthe heat sink 149. As shown, the reflector 300 is formed as a slipcollar with a flare 300 a at the end such that when the LED assembly 130is inserted, the light directed primarily toward the base encounters thereflector 300 and is reflected out the exit surface 308. The LEDassembly 130 is mounted as previously described to trap the reflector300 between the heat sink 149 and the LED assembly 130. The reflectormay also be mounted on the dissipating portion 153 of the heat sink. Thereflector 300 may also be mounted to the heat sink 149 or LED assembly130 using separate fasteners, adhesive, friction fit, mechanicalengagement such as a snap-fit connection, welding or the like.

In one embodiment, the reflector 300 is made in two portions 350 and 352that together surround the heat conducting portion or tower 152 andconnect to one another using snap fit connectors 354 to clamp the heatsink therebetween as shown in FIGS. 76-84. In the illustrated embodimentthe two portions are identical such that a single component may be usedalthough the two portions may be different. The snap fit connectors 354may comprise a deformable tang 356 on one reflector portion that isreceived in a mating receptacle 358 on the other reflector portion whereeach reflector portion comprises one tang and one receptacle. However,two tangs may be formed on one portion and two receptacles may be formedon the other portion. The tangs 356 may be inserted into the receptacles358 such that locking surfaces 360 on the tangs 356 are disposed behindthe receptacles 358. The tangs and/or receptacles may be made ofresilient material to allow these components to deflect as the tangs 356are inserted into the receptacles 358. The two portions 350 and 353 maybe brought into engagement with one another with the heat sink 152trapped between the portions. The reflector 300 may comprise legs 366that are supported on protrusions 368 formed on the heat sink 152 toproperly vertically position the reflector 300 on the heat sink 152 andto maintain the reflector in the proper orientation relative to theLEDs. The reflector 300 may also include protrusions 370 that extendtoward the interior of the reflector and that engage the lateral sidesof the protrusions 368 or other heat sink structure to fix the angularrelationship between the reflector and heat sink such that the reflectoris prevented from rotating relative to the heat sink. The structure ofthe reflector described above may be used with any of the embodiments ofthe reflector and in any of the lamps described herein.

The reflector 300 is dimensioned such that the LED assembly 130, heatsink 149 and reflector 300 may be inserted through the opening 304 inthe neck of a BR type enclosure 302. The LED assembly 130, heat sink 149and reflector 300 are inserted into the BR enclosure 302. The BRenclosure 302 may be secured to the heat sink 149 as previouslydescribed using adhesive or other connection mechanism. The enclosure302 comprises a body 306 that is typically coated on an interior surfacewith a highly reflective material such as aluminum to create areflective surface 310 and an exit surface 308 through which the lightexits the lamp. The exit surface 308 may be frosted or otherwise treatedwith a light diffuser material. Moreover, the reflector 300 may bemounted to the enclosure 302 rather than to the LED assembly and/or heatsink.

As previously explained, the reflector 300 may be positioned such thatit reflects some of the light generated by the LED assembly 130.However, at least a portion of the light generated by the LED assembly130 may not be reflected by the reflector 300. At least some of thislight may be reflected by the reflective surface 310 of the enclosure302. Some of the light generated by the LED assembly 130 may also beprojected directly out of the exit surface 308 without being reflectedby the primary reflector 300 or the reflective surface 310.

FIGS. 27-37 show an embodiment of a PAR type lamp that uses the LEDassembly 130, heat sink with the tower arrangement 149 and electricalinterconnect 150 as previously described. In a PAR type lamp the lightis emitted in a directional pattern. Standard PAR bulbs are reflectorbulbs that reflect light in a direction where the beam angle is tightlycontrolled using a parabolic reflector. PAR lamps may direct the lightin a pattern having a tightly controlled beam angle such as, but notlimited to, 10°, 25° and 40°. The bulb shown in FIG. 22 may be used as asolid state replacement for such a reflector type PAR bulb.

The lamp comprises a base 102, heat sink 149, electrical interconnect150 and LED assembly 130 as previously described. As previouslyexplained, the LED assembly 130 generates an omnidirectional lightpattern. To create a directional light pattern, a primary reflector 400is provided that reflects light generated by the LED assembly 130generally in a direction along the axis of the lamp. Because the lamp isintended to be used as a replacement for a PAR type lamp, the reflector400 may reflect the light in a tightly controlled beam angle. Thereflector 400 may comprise a parabolic surface 400 a such that lightreflecting off of the reflector 400 is reflected generally along theaxis of the lamp to create a beam with a controlled beam angle.

The reflector 300 is preferably made of a specular material. Thespecular reflectors may be injection molded plastic or die cast metal(aluminum, zinc, magnesium) with a specular coating. The specularmaterial could also be a formed film, such as 3M's Vikuiti ESR (EnhancedSpecular Reflector) film. It could also be formed aluminum, or a flowerpetal arrangement in aluminum using Alanod's Miro or Miro Silver sheet.In some embodiments, the reflector may be a diffuse or Lambertianreflector and may be made of a white highly reflective material such asinjection molded plastic, white optics, PET, MCPET, or other reflectivematerials. The reflector may reflect light but also allow some light topass through it.

The reflector 400 is mounted in the lamp such that it surrounds the LEDassembly 130 and reflects some of the light generated by the LEDassembly. In some embodiments, the reflector 400 reflects over 20% ofthe light generated by the LED assembly 130. In other embodiments, thereflector 400 reflects about at least 40% of the light generated by theLED assembly 130 and in other embodiments, the reflector 400 may reflectabout at least 60% of the light generated by the LED assembly 130.Because the reflector 400 may be at least 90% reflective the more lightthat hits the reflector 400 the more efficient the lamp. This is incontrast to the reflective aluminum coating typically found on astandard PAR lamp enclosure that is approximately 80% reflective.Because the lamp is used as a PAR replacement, the beam angle is tightlycontrolled where the light that is reflected from the reflector 400 isemitted from the lamp at a tightly controlled the beam angle.

The reflector 400 is mounted such that the light emitted from the LEDassembly 130 is emitted at or near the focus of the parabolic reflector400. In some embodiments, the two tiered arrangement of LEDs, asdescribed for example with respect to FIGS. 1-5, may be disposed suchthat the light is emitted at or near enough to the focus of thereflector 400 that the beam angle of the light that is emitted from thelamp is at the desired beam angle. In some embodiments, one tier of LEDsmay be disposed on the focus of the reflector and the other tier of LEDsmay be positioned slightly off of the focus of the parabolic reflector.In some embodiments, a single tier of LEDs may be used that are disposedon the focus of the reflector. Further, the two tiers of LEDs may beused where the vertical pairs of LEDs are disposed under a single lenssuch that light emitted from the pairs of LEDs originates at the focusof the reflector 400. Other arrangements of the LEDs may be madeprovided that the reflector reflects the light at the desired beamangle. While a one tier and a two tier LED assembly have been described,three or more tiers may be used in the LED assembly.

The reflector 400 may be mounted on the heat sink 149 or LED assembly130 using a variety of connection mechanisms. In one embodiment, thereflector 400 comprises a sleeve that is mounted on the heat conductingportion or tower 152 of the heat sink 149 as previously described. TheLED assembly 130 is mounted as previously described to trap thereflector 400 between the heat sink 149 and the LED assembly 130. Thereflector 400 may also be mounted to the heat sink 149 or LED assembly130 using separate fasteners, adhesive, friction fit, mechanicalengagement such as a snap-fit connector, welding or the like. Moreover,the reflector 400 may be mounted to the enclosure 402 rather than to theLED assembly and/or heat sink.

The reflector 400 is dimensioned such that the LED assembly 130, heatsink 149 and reflector 400 may be inserted through the opening 404 inthe neck of a PAR type enclosure 402. To assemble the lamp, the LEDassembly 130, heat sink 149 and reflector 400 are inserted into the PARenclosure 402. The enclosure 402 is secured to the heat sink 149 aspreviously described using adhesive or other connection mechanism. Theenclosure 402 comprises a body 404 that comprises a parabolic reflectivesurface 406 that is typically coated with a highly reflective materialsuch as aluminum and an exit surface 408 through which the light exitsthe lamp. The exit surface 408 may be frosted or otherwise treated witha light diffuser material.

As previously explained, the reflector 400 may be positioned such thatit reflects some of the light generated by the LED assembly 130.However, at least a portion of the light generated by the LED assembly130 may not be reflected by the reflector 400. At least some of thislight may be reflected by the parabolic reflective surface 406 of theenclosure 402. Some of the light generated by the LED assembly 130 maybe projected out of the exit surface 408 without being reflected by thereflector 400 or the reflective surface 406.

One potential issue with using a single, large parabolic reflector 400that surrounds the entire LED assembly 130, as described above, is thatsome of the light may be reflected in a generally horizontal plane suchthat it circles the reflector 400 and reflects multiple times from thereflector 400 before being emitted from the lamp. Such a situationresults in a loss of efficiency. To lower these losses, a parabolicreflector 500 may be provided for each LED 127 such that each LED 127has associated with it a relatively small parabolic reflector 500 thatreflects light from that LED as shown in FIGS. 38-49. In someembodiments, the reflector 500 and associated LED 127 may form a unitthat is mounted on the LED assembly 130. In some embodiments, the two(or additional) tiered arrangement of LEDs may be used where the LEDs127 and reflectors 500 are horizontally offset from one another suchthat the light emitted from each LED 127 is not blocked by thevertically adjacent LED and reflector. In some embodiments, a singletier of LEDs 127 and associated reflectors 500 may be used. In theillustrated embodiment a two tiered arrangement of LEDs is shown whereeach vertical pair of LEDs is associated with a single reflector. Thereflectors 500 are formed as part of a unitary assembly or sleeve 501such that all of the reflectors may be mounted on the LED assembly as aunit. Other arrangements of the LEDs 127 and reflectors 500 may be usedprovided that the reflectors may reflect the light at the desired beamangle. The reflectors 500 and LEDs 127 may be in a one-to-onerelationship or a single reflector may be used with more than one LED,but with fewer than all of the LEDs of LED array 130. The reflectors 500may be specular. Moreover, the LED assembly may be modified to allow themounting of the reflectors with the associated LEDs. For example, theLEDs may need to be more widely spaced to accommodate the reflectors(compare FIG. 35 to FIG. 47) or the LED assembly may need to be madesmaller.

FIGS. 50-64 shows an embodiment of a lamp that uses the base 102, LEDassembly 130, heat sink with the tower 149, and electrical interconnect150 as previously described in a PAR type lamp. The bulb shown in FIGS.50-64 may be used as a solid state replacement for such reflector typebulbs. As previously explained, the LED assembly 130 generates anomnidirectional light pattern. To create a directional light pattern, aprimary reflector 600 is provided that reflects light generated by theLED assembly 130 through a secondary focal point 601. The reflector 600may comprise an elliptical specular reflecting surface 600 a thatreflects the light through the secondary focal point 601. In someembodiments, the reflector may be a diffuse or Lambertian reflector andmay be made of a white highly reflective material such as injectionmolded plastic, white optics, PET, MCPET, or other reflective materials.The reflector may reflect light but also allow some light to passthrough it. The reflector 600 may be a diffuse reflector; however, insome embodiments the reflector surface must be specular. The specularreflector may be injection molded plastic or die cast metal (aluminum,zinc, magnesium) with a specular coating. Such coatings could be appliedvia vacuum metallization or sputtering, and could be aluminum or silver.The specular material could also be a formed film, such as 3M's VikuitiESR (Enhanced Specular Reflector) film. It could also be formedaluminum, or a flower petal arrangement in aluminum using Alanod's Miroor Miro Silver sheet. The light reflected by an elliptical reflector 600is reflected through the secondary focal point 601 and generally towardthe exit surface of the lamp but is reflected at a widely divergent beamangle. The secondary focal point 601 of the reflected light is used as avirtual light source as will be described.

The reflector 600 is mounted in the lamp such that it surrounds the LEDassembly 130 and reflects most of the light generated by the LEDassembly. In some embodiments, the reflector 600 reflects about at least20% of the light generated by the LED assembly 130. In otherembodiments, the reflector 600 reflects about at least 40% of the lightgenerated by the LED assembly 130 and in other embodiments, thereflector 600 may reflect about at least 60% of the light generated bythe LED assembly 130. Because the reflector 600 may be at least 90%reflective the more light that hits the reflector the more efficient thelamp. This is in contrast to the reflective aluminum coating typicallyfound on a standard PAR lamp enclosure that is approximately 80%reflective.

The reflector 600 may be mounted on the heat sink 149 or LED assembly130 using a variety of connection mechanisms. In one embodiment, thereflector 600 is formed as a slip sleeve and is mounted on the heatconducting portion 152 of the heat sink 149 and the LED assembly 130 ismounted as previously described to trap the reflector 600 between theheat sink 149 and the LED assembly 130. The reflector 600 may also bemounted to the heat sink 149 or LED assembly 130 using separatefasteners, adhesive, friction fit, mechanical engagement such as asnap-fit, welding or the like. Moreover, the reflector 600 may bemounted to the enclosure 602 rather than to the LED assembly and/or heatsink.

The reflector 600 is dimensioned such that the LED assembly 130, heatsink 149 and reflector 600 may be inserted through the opening 604 inthe neck of a PAR style enclosure 602. To assemble the lamp, the LEDassembly, heat sink and reflector 600 are inserted into the PARenclosure 602. The enclosure 602 is secured to the heat sink 149 aspreviously described using adhesive or other connection mechanism.

Referring to FIGS. 61-64, the enclosure 602 comprises a body 606 that istypically coated with a highly reflective material such as aluminum andan exit surface in the form of a lens 702 through which the light exitsthe lamp. The lens 702 focuses the light from the virtual source 601(reflector focal point) to create a beam of light at the desired beamangle. The entry surface of lens 702 includes a plurality ofsubstantially triangular concentric rings 704, each having non-verticalsides. By the term “non-vertical,” what is meant is that neither side ofthe triangle formed by the cross-section of the concentric ring isparallel to the direction in which the light is emanated from virtualsource 601.

Exit surface 712 of lens 702 includes surface texturing. This surfacetexturing provides additional diffusion for light exiting the lightengine. This surface texture is represented in FIG. 61 schematically;however, could consist of dimpling, frosting, or any other type oftexture that can be applied to a lens for a lighting system. Finally, itshould be observed that exit surface 712 is slightly curved. However,embodiments of the invention can include a flat exit surface, or acurved entry service. Both surfaces of the lens could be flat or curved.Several examples will be presented herein.

A lens 702 according to example embodiments can be made in various ways.The example of FIGS. 61-64 is a schematic illustration. The actualnumbers of concentric rings, and the actual size and spacing of therings, are not to scale. The cross-section of the concentric features inFIG. 61 is an equilateral triangle, but other triangular shapes can beused. Additionally, the vertex angle of the equilateral triangles inFIG. 1 is constant, as is the spacing of the concentric circularfeatures. Varying these properties of the lens features can allow theformation of differing beam patterns. Either the vertex angle of thetriangles or the spacing interval of the concentric features across thediameter of the lens can change or have a gradient applied. For example,in some embodiments, the substantially triangular concentric rings canbe spaced at a fixed interval from about 0.1 mm to about 5 mm across theradius of the lens. In some embodiments, they can be spaced at a fixedinterval from between about 0.2 mm to about 3 mm. In some embodimentsthey can be spaced a fixed interval from between about 0.3 mm to about 2mm. In some embodiments they can be spaced at a fixed interval of about0.5 mm. A gradient can also be applied to the spacing so that theinterval varies. For example, the interval can be smaller near thecenter of the lens and progress to a larger interval closer to the edgeof the lens, or vice versa. Multiple discrete intervals can also beused.

FIG. 62 shows a close-up, cross-sectional view of a portion of entrysurface of lens 712. Substantially triangular concentric rings arevisible, spaced at an interval of 0.500 mm. As can be observed in thefigure, the height of the features is 0.635 mm. As can also be observed,a gradient is applied to the vertex angle of the features. Vertex 802has an angle of 43.0°, and the angle decreases from left to right tovertex 804 with an angle of 40.0°. All the way to the right, vertexangle 806 increases again to an angle of 40.5°.

FIG. 63 shows a close-up, cross-sectional view of a portion of entrysurface of lens 712. Substantially triangular concentric rings arevisible, spaced and interval of 0.500 mm. These rings follow the curvedcontour of the entry or LED-facing surface of the lens. As can beobserved in the figures, the vertex angle of the feature varies.Vertices 902 with a greater height have an angle of 60.0°, and vertices904 have an angle of 90.0°.

FIG. 64 shows a close-up, cross-sectional view of a portion of entrysurface of lens 712. Substantially triangular concentric rings arevisible, again spaced at an interval of 0.500 mm. As can be observed inthe figure, a gradient is applied to the vertex angle of the features.Vertex 1002 has an angle of 63.0°, and the angle decreases from left toright in the figure until vertex 1004 with an angle of 61.0°, in 0.40°increments.

A lens according to example embodiments of the invention can be madefrom various materials, including acrylic, polycarbonate, glass,polyarylate, and many other transparent materials. The textured exitsurface of the lens can be created in many ways. For example, a smoothsurface could be roughened. The surface could be molded with texturedfeatures. Such a surface may be, for example, prismatic in nature. Alens according to embodiments of the invention can also consist ofmultiple parts co-molded or co-extruded together. For example, thetextured surface could be another material co-molded or co-extruded withthe portion of the lens with the substantially triangular concentricrings.

The spacing, angles, and other features of the concentric rings can bevaried either across lenses, or within the surface of a single lens inorder to achieve various lighting effects. As examples, the vertex angleof the concentric rings can be varied. In some embodiments, the angle isfrom about 35° to about 90°. In some embodiments, the angle ranges fromabout 40° to about 65°. The angle can be constant across the radius ofthe lens, can have a gradient applied, or can vary in other ways, aswith some of the examples presented herein. The spacing of theconcentric features can similarly vary.

As further specific examples, lenses with the following specificationshave been tested and shown to be effective for various beam shapingeffects. These first examples all have a ring spacing across the radiusof the lens of approximately 3 mm. A lens with vertex angles rangingfrom 70° to 86°, in one degree increments produces a wide beam. A lenswith some vertex angles varying from 65° to 71°, and some angles fixedat 90° with the increment of the former being about 1° produces a floodpattern. A lens with some angles varying in 1° increments between 60°and 71°, some fixed at 71°, and others varying in 1° increments backfrom 71° to 68° produces a forward pattern. A set of fixed-anglefeatures with a vertex angle of 40° produces a spot pattern with a beamangle of approximately 20°.

The following example embodiments that have been tested have a ringspacing across the radius of the lens of approximately 2 mm. A lens withrings having vertex angles varying from 60° to 84° in 1° incrementsproduces a wide pattern. A lens with feature vertex angles varying from60° to 70° in 1° increments, and additional rings having a fixed angleof approximately 90°, produces a flood pattern. A lens with somevertices varying from 60° to 69° in half-degree increments, four fixedrings with 69° vertices, and two additional rings with 68° and 69°vertices produces a forward pattern. A fixed vertex angle of 40° acrossthe lens again produces a spot pattern with a beam angle ofapproximately 20°.

Example embodiments that have been tested with a ring spacing of 1 mminclude a lens with a range of vertex angles varying from 70° to 82.25°in 0.25° increments, which produced a wide beam pattern. A lens with 50rings, 25 with a fixed vertex angle of 90°, and 25 with a varying vertexangle from 60° to 72° in 0.25° increments produced a flood pattern. Alens with some rings varying in 0.50° increments from a vertex angle of60° to a vertex angle of 73°, and some varying in 0.25° increments froman angle of 73° to angle of 68.25°, and three at a fixed vertex angle of73°, produced a forward pattern. Finally, a lens with rings having afixed vertex angle of 40° again produced a spot pattern with a beamangle of approximately 20°.

In addition to the detailed examples presented herein with a 0.5 mmspacing for the triangular concentric rings across the radius of thelens, the following examples were tested. These include rings with arange of vertex angles from 60° to 80° in 0.2° increments, whichproduced a wide beam pattern. A lens with 101 rings, 51 of which havevertex angles from 60° to 70° in 0.2° increments, and 50 of which have afixed vertex angle of 90°, produced a flood pattern. A lens with 101rings where 19 of them had a fixed vertex angle of 75°, and theremainder were split with vertex angles ranging from 60° to 75° in 0.25°increments and 75° to 70° in 0.25° increments produced a forwardpattern. In addition to the above, it was found that maintaining aconstant vertex angle across the radius of the lens but adjusting theangle from lens to lens produced a spot pattern which variedproportionately in angular size. For example, using features with avertex angle of 35° produced a spot pattern with a beam angle of 32°.Using features with a vertex angle of 45° produced a spot pattern with abeam angle from 11° to 15° depending on the size of the LED source. Asuitable lens for use in the lamp of the invention is disclosed in U.S.patent application entitled “Beam Shaping Lens and LED Lighting SystemUsing Same”, application Ser. No. 13/657,421, filed on Oct. 22, 2012,which is incorporated herein by reference in its entirety.

As is evident from the foregoing description, a lamp constructed usingthe primary reflector and the lens 702 may produce light with a beamangle that varies from a wide angle flood pattern to a tightlycontrolled spot pattern. As a result, the construction allows the lampto replace either a wide angle lamp such as a BR lamp or a narrow beamangle lamp such as a PAR lamp.

As previously explained, the reflector 600 as described herein may bepositioned such that the reflector 600 reflects a portion of the lightgenerated by the LED assembly 130. However, at least a portion of thelight generated by the LED assembly 130 may not be reflected by thereflector 600. At least some of this light may be reflected by thereflective surface of the enclosure. Some of the light generated by theLED assembly may be projected to the lens portion without beingreflected by the reflector or the enclosure.

As was explained with respect to the previously described embodiments ofa directional lamp, at least some of the light generated by the LEDassembly 130 may be directed toward the exit surface of the lamp. An LED127 positioned as described herein may have a beam angle ofapproximately 120° such that at least some of the light emitted from theLEDs 127 is directed directly out the exit surface. In order to capturethis light and shape the beam, a reverse or downward facing reflector1200 may be added as shown in FIGS. 65-75. The reverse reflector 1200captures light that is projected toward the exit surface of the lamp andreflects that light from reflecting surface 1200 a to the primaryreflector such that the light may be projected in the desired beam angleby the primary reflector as described above. Any suitable reflector maybe used as the reverse reflector to redirect the light toward theprimary reflector.

Because the PAR and BR style lamps are intended to provide directionalbeams, asymmetrical LEDs may be advantageously used in variousembodiments of the invention. Because the LED assembly 130 uses aplurality of LEDs 127 in the LED array 128, all of the LEDs 127 orselected ones of the LEDs may be asymmetrical LEDs. In some asymmetricalLEDs, the LED optic is shaped to produce the asymmetric beam.Embodiments could use an overmolded asymmetric optic (MDA style). Theasymmetric beam may be arranged to directly exit the lamp from the exitsurface without being reflected by any reflector surface. The asymmetricbeam may also be arranged such that the beam is directed to a desiredlocation on one of the reflectors described herein.

Depending on the embodiment, in the various embodiments describedherein, the primary reflector may be configured to reflect light outtowards the exit and/or at a secondary or outer reflector such that thereflector formed on the inner surface of the enclosure. Depending on theembodiment, the primary reflector can point upward, downward or be flat.The primary reflector may be positioned above, below or between LEDs onthe LED assembly 130. Depending on the embodiment, the outer orsecondary reflector, such as the reflector formed on the inner surfaceof the enclosure may be specular or diffuse.

The reflectors as described herein may also be used in anomnidirectional lamp such as the A19 style of lamp shown, for example,in FIG. 1. In an omnidirectional lamp the reflector may be used toprovide a greater degree of up lighting, i.e. light toward the free endof the lamp opposite the Edison connector, if desired. In someembodiments, the reflector may have the same shape and size for a BRstyle lamp, a PAR style lamp and an omnidirectional lamp such as an A19style lamp where the light is shaped using the material of thereflector. In an omnidirectional style lamp the reflector may be made ofa semitransparent or translucent material such that some of the light isreflected but other light is allowed to pass through the reflector. Suchan arrangement provides less directional reflection and a moreomnidirectional pattern while still providing some light shaping. In aBR style light the reflector may be made of a white material thatprovides reflection of the light but in a somewhat diffused pattern. Ina PAR style lamp the reflector may be made of or coated in a highlyreflective material such as but not limited to aluminum or silver toprovide specular reflection and a tightly shaped beam. The reflectorsmade with the various surfaces described herein may be of the same sizeand shape for the omnidirectional lamp and the directional lamps suchthat the same type of reflector may be used with the only change beingthe material in the different forms of the lamp.

In the various embodiments described herein, the LED assembly is in theform of an LED tower within the enclosure, the LEDs are mounted on theLED tower in a manner that mimics the appearance of a traditionalincandescent bulb. As a result, the LEDs can be positioned on the LEDtower in the same area that the glowing filament is visible in atraditional incandescent bulb. As a result, the lamps of the inventionprovide similar optical light patterns to a traditional incandescentbulb and provide a similar physical appearance during use. The mountingof the LED assembly on the tower, such that the LEDs are centered on thelongitudinal axis of the lamp and are in a position that is centrallylocated in the enclosure, provides the look of a traditionalincandescent bulb. Centrally located means that the LEDs are disposed onthe tower in the free open space of the enclosure as distinguished frombeing mounted at or on the bottom of the enclosure or on the enclosurewalls. In certain embodiments, the LEDs are positioned in a band aboutthe tower such that the high intensity area of light produced from theLEDs appears as a glowing filament of light when in use. The band ofLEDs could be produced by single or multiple rows or strings of LEDsthat are closely packed together within the band or offset from eachother within the band. Various configurations are possible where theLEDs are positioned in a band or concentrated in a particular regionabout the LED tower to produce a filament-type appearance when in useand when viewed from different directions. In some embodiments, the LEDsmay be arranged on the tower such that they are in a relatively narrowband that is located near the optical center of the enclosure. In someembodiments, the LEDs may be arranged on the filament tower in a narrowband that extends around the periphery of the tower where the height ofthe band (in the dimension along the axis of the tower) is smaller thanthe diameter of the tower. As a result, the when the lamp is viewed fromthe side the LEDs create a bright light source that that extends acrossthe lamp and appears as a relatively bright line inside of theenclosure. The band or concentrated region of LEDs can comprise lessthan 50%, less than 40% or even less than 30% of the exposed surfacearea of the tower. In some embodiments, the LED region is disposedtoward one end of the array such that the region is offset from thecenter of the tower where the tower extends from the base to support theLED array at the desired location within the enclosure. The LEDs havebeen described as a band that extends around the periphery of the tower.In addition to extending around the periphery of the tower the LEDs alsoextend around or encircle the longitudinal axis of the lamp. In someembodiments, the tower is disposed along the longitudinal axis of thelamp such that the LEDs surround or extend around both the longitudinalaxis of the lamp and the tower as shown in the Figures. In someembodiments the LEDs may be disposed such that the LEDs do not surroundthe tower but still surround the longitudinal axis of the lamp.Referring to FIG. 85, for example, the LED assembly 130 may be mounteddirectly to the heat dissipating portion 154 of the heat sink 149 usingextensions 190 or similar structure where the tower 152 is eliminated.In such an arrangement the LEDs 127 surround the longitudinal axis ofthe lamp even though the LEDs do not surround the heat sink. Otherarrangements are also possible where, for example, a tower 152 isprovided but the LEDs are arranged beyond the end of the tower 152. Insuch an arrangement the LEDs 127 surround the longitudinal axis of thelamp even though the LEDs do not physically surround the heat sink.

Because, in some embodiments, the LEDs are closely packed or positionedin a more concentrated or more dense region of the tower, the tower isused as a heat sink that provides a thermal path from the LEDs to thebase of the bulb. In some embodiments the base acts as part of the heatsink and may include fins or other surface area or mass increasingfeatures. In some embodiments, the heat sink portion of the baseincludes an integral support or a portion of the tower over which theLED tower fits or to which the LED tower is connected such that athermal path is from the LEDs through the filament tower to the supportand/or to the base. In some embodiments, the base and support is anintegral piece, and in other embodiments it is different pieces. In someembodiments, the support is part of the tower and/or thermal path, andin others it is not. In some embodiments, the support and/or base is nota major part of the thermal path in that the support and/or base is madeof a poor thermal conductor, and the LED tower forms part of the thermalpath to other portions of the bulb, such as the enclosure of the bulb,for example through thermally conductive gas or liquid within theenclosure. In some embodiments, the LED tower itself can providesufficient thermal protection for the LEDs.

In some embodiments, depending on the LEDs used, the exit surfaces inthese and other embodiments may be made of glass which has been dopedwith a rare earth compound, in this example, neodymium oxide. Such anoptical element could also be made of a polymer, including an aromaticpolymer such as an inherently UV stable polyester. The exit surface istransmissive of light. However, due to the neodymium oxide in the glass,light passing through the dome of the optical element is filtered sothat the light exiting the dome exhibits a spectral notch. A spectralnotch is a portion of the color spectrum where the light is attenuated,thus forming a “notch” when light intensity is plotted againstwavelength. Depending on the type or composition of glass or othermaterial used to form the optical element, the amount of neodymiumcompound present, and the amount and type of other trace substances inthe optical element, the spectral notch can occur between thewavelengths of 520 nm and 605 nm. In some embodiments, the spectralnotch can occur between the wavelengths of 565 nm and 600 nm. In otherembodiments, the spectral notch can occur between the wavelengths of 570nm and 595 nm. Such systems are disclosed in U.S. patent applicationSer. No. 13/341,337, filed Dec. 30, 2011, titled “LED Lighting UsingSpectral Notching” which is incorporated herein by reference in itsentirety.

Referring to FIG. 86 an alternate embodiment of the lamp is showncomprising the base 102, lamp electronics 110, heat sink and tower 149,LED assembly 130 and electrical interconnect 150. A reflector 1700 ismounted to the heat sink 149 to form a directional lamp such as a PAR orBR style lamp. The reflector 1700 may be formed of a thermallyconductive material such as metal and may be formed, for example, ofaluminum. The reflective surface 1702 of reflector 1700 may be shaped toproduce a directional light pattern of a specific shape. For example,the reflective surface 1702 may be formed as a parabolic reflector or itmay have other shapes that deliver a directional beam of light from thelamp. In other embodiments the reflective surface 1702 may have othershapes to produce a desired directional pattern and in some embodimentsthe formation of the directional light pattern may be created by thelens 1704 such that the reflective surface 1702 may have any shape thatreflects the light toward the lens 1704. The reflective layer 1702 maybe formed as a metalized layer, a reflective plastic layer such as whiteplastic such as PET or MCPET, a reflective paint or other suitablematerial. The reflective layer 1702 may also be formed integrally withthe reflector 1700 such as by polishing the interior surface of thereflector 1700. The reflective surface may be made of a specularmaterial. The specular reflector may be die cast metal (aluminum, zinc,magnesium). The specular reflector, if not the same component as theheat conductive PAR shaped member, may also be an injection moldedplastic insert that is metalized with aluminum or silver to create areflective surface. Where the specular reflector and the heat conductivemember is the same component it may be made of die cast aluminum,magnesium, zinc but it also may be stamped, deep drawn, hydroformed orspun aluminum. The specular surface of the reflector may be formed bypolishing, such as by polishing the aluminum surface, or by vacuummetalized aluminum or by other process.

The reflector 1700 is formed of a thermally conductive material such asmetal and may be formed, for example, of aluminum. Other thermallyconductive materials, in addition to metals, such as ceramic may also beused. The reflector 1700 is mounted to the heat sink 149 such that thereflector 1700 is thermally coupled to the heat sink 149. By thermallycoupling the heat sink 149 to the reflector 1700, the reflector 1700forms part of the heat sink for the lamp and increases the exposedsurface area of the heat sink to facilitate heat transfer from the LEDassembly 130 to the ambient environment. The thermal coupling of theheat sink 149 to the reflector 1700 may be made by providing a directsurface to surface contact between the heat sink 149 and the reflector1700. In one embodiment, the reflector 1700 is formed with an inwardlyfacing flange 1706 at a first end thereof. The flange 1706 has anannular shape such that the tower portion of the heat sink 149 and theLED assembly 130 may be inserted through the aperture 1708 into theinterior of the reflector 1700. The flange 1706 is seated on a surface1710 of the heat sink 149 such that the surface of the flange 1706 andthe surface 1710 of the heat sink are in good surface to surface contactsuch that heat may be transferred from the heat sink 149 to thereflector 1700. The flange 1706 and surface 1710 may have generallycircular shapes where the lamp has a traditional generally cylindricalshape; however, the reflector 1700 and heat sink 149 may have a varietyof shapes. While in the illustrated embodiment, the flange 1706 of thereflector 1700 and the surface 1710 of the heat sink 149 are in directsurface to surface contact with one another, intervening elements may bepresent provided efficient thermal transfer occurs between the heat sink149 and the reflector 1700. For example, thermal adhesive, a metal layeror the like may be disposed between the heat sink 149 and the reflector1700.

To attach the reflector 1700 to the heat sink 149 buttons or nubs 1712may be formed on the heat sink surface 1710 that form protuberances thatextend from the surface (FIG. 87). The buttons or nubs 1712 may beprotrusions integrally formed with the heat sink 149 or the buttons ornubs 1712 may be separate elements attached to the heat sink 149. Thenubs or buttons 1712 are inserted through holes 1714 formed in theflange 1706 such that they are exposed to the interior of the reflector1700. The nubs or buttons are then deformed or smashed to create a head1716 that presses the flange 1706 against the surface 1708 of heat sinkand holds the reflector 1700 on the heat sink 149. In some embodiments,a separate fastener may be used such as a screw, rivet, snap-fitconnector or other similar fastener mechanism. Welding, brazing,adhesive may also be used as the fastener mechanism. The fastenermechanism holds the reflector 1700 against the heat sink 149 such thatheat may be thermally conducted from the heat sink 149 to the reflector1700 and dissipated from the lamp via the exposed surface of thereflector 1700. The reflector 1700 may also be attached to the heat sinkin the same manner as the reflector housing of FIG. 90 as shown in FIG.92. However, in the embodiment of FIGS. 90 and 92 the heat dissipatingportion of the heat sink is substantially covered by the reflectorhousing such that the reflector housing acts as the primary heatconductive surface to the ambient environment. In the embodiment of FIG.86 the heat dissipating portion of the heat sink 149 is exposed suchthat heat transfer is made through the reflector 1700 and the heatdissipating portion.

The use of the reflector 1700 as the heat sink may be particularlyuseful in higher power lamps, such as 75 watt, 90 watt equivalent lampsand higher power lamps, where more heat is generated that may bedissipated to the ambient environment over the relatively large surfacearea of the heat sink and reflector. While the arrangement isparticularly beneficial with higher power lamps the arrangement may beused in any size lamp.

A lens 1704 may cover the light exit opening 1720 in the reflector 1700to diffuse and/or focus the light emitted from the lamp. In someembodiments the lens 1704 may comprise a glass or plastic lens and mayhave a diffusing layer formed as part of the lens or a diffusing layermay be formed on the lens. The diffusing layer may comprise a coating onthe lens, etching of the lens, the property of the lens material orother diffusing mechanism. To mount the lens 1704 in the reflector 1700the distal edge 1724 of the reflector 1700 may be formed to have achannel 1722 that surrounds and holds a peripheral edge of the lens1704. In some embodiments, the lens 1704 may be located in the reflector1700 and the edge 1724 of the reflector 1700 may be rolled to create thechannel 1722 that surrounds and holds the lens 1704. In otherembodiments the lens may be attached by a separate attachment mechanismincluding separate fasteners, adhesive or the like.

FIG. 88 shows an alternate embodiment of a lamp that is similar to thelamp of FIGS. 86 and 87 except that a secondary reflector 1730 islocated in the center of the reflector 1700 substantially along thelongitudinal axis of the lamp between the LED assembly 130 and the lens1704. The secondary reflector 1730 is dimensioned and shaped to reflectlight that would otherwise be emitted from the LED assembly directly outof the lens 1704. The secondary reflector 1730 reflects at least aportion of this light back toward the reflector 1700 where it isreflected from the interior surface 1702 of the reflector before exitingthe lamp through lens 1704. The secondary reflector 1730 may comprise amember mounted to the tower portion of heat sink 149, to the LEDassembly 130 and/or to the reflector 1700 and may have a reflectivesurface 1732 made of a reflective material such as PET, MCPET,reflective paint, metalized surface or the like. In some embodiments,the secondary reflector may be made entirely of reflective material suchas being molded from reflective plastic such as PET or MCPET MPET. Theuse of the secondary reflector 1730 prevents light from exiting directlyout of the lens 1704 where the light may otherwise create a visible “hotspot” or “bright spot” of light at the center of the lens. This light isreflected back into the reflector 1700 where it is mixed with otherlight from the LED assembly and is reflected from surface 1702 beforeexiting through lens 1704.

FIG. 89 shows an alternate embodiment of a lamp that is similar to thelamp of FIG. 88 except that a secondary reflector 1740 having adownwardly directed reflective surface 1742 is located in the center ofthe lens 1704 substantially along the longitudinal axis of the lamp. Thesecondary reflector 1740 performs substantially the same function as thesecondary reflector 1730 in FIG. 88. The secondary reflector 1740 may beinserted molded into the lens 1704 such that the lens 1704 and secondaryreflector 1740 form an integral one-piece assembly.

Referring to FIG. 90 an alternate embodiment of the lamp, such as adirectional lamp such as a PAR or BR style lamp, is shown comprising thebase 102, lamp electronics 110, heat sink and tower 149 LED assembly 130and electrical interconnect 150. A reflector housing 1750 is mounted tothe heat sink 149. The reflector housing 1750 may be formed to have anysuitable shape. The reflector housing 1750 may be formed of a thermallyconductive material such as metal and may be formed, for example, ofaluminum. The reflector housing is mounted to the heat sink 149 suchthat the reflector housing is thermally coupled to the heat sink 149. Bythermally coupling the heat sink 149 to the reflector housing 1750, thereflector housing 1750 forms part of the heat sink and increases thesurface area of the heat sink to facilitate heat transfer from the LEDassembly 130 to the ambient environment. The thermal coupling of theheat sink 149 to the reflector housing 1750 may be made by providing adirect surface to surface contact between the heat sink and thereflector.

A separate reflector 1752 is positioned in the housing 1750 to reflectlight generated by the LED assembly out of lens 1754. The reflectivesurface 1756 of the reflector 1752 may comprise a reflective layer suchas a metalized layer, a reflective plastic layer such as MPET, areflective paint or other suitable material. The reflective layer mayalso be formed integrally with the reflector such as by polishing theinterior surface. The reflector may be made of a specular material. Thespecular reflector may be die cast metal (aluminum, zinc, magnesium), orother thermally conductive material with a specular coating. Thespecular material could also be a formed film, such as 3M's Vikuiti ESR(Enhanced Specular Reflector) film. It could also be formed aluminum. Insome embodiments, the reflector may be a diffuse or Lambertian reflectorand may be made of a white highly reflective material such as injectionmolded plastic, white optics, PET, MCPET, or other reflective materials.In one embodiment the entire reflector may be made of a white reflectivematerial such as molded plastic, such as PET or MCPET. The reflector1752 may reflect most of the light generated by the LED assembly 130 butalso allow some light to pass through it. The reflector 1752 may be adiffuse reflector; however, in some embodiments the reflector surfacemust be spectral. The specular reflector may be injection molded plasticor die cast metal (aluminum, zinc, magnesium) with a specular coating.Such coatings could be applied via vacuum metallization or sputtering,and could be aluminum or silver. The specular material could also be aformed film. The light reflected by the reflector is reflected generallytoward the exit opening 1758 of the reflector housing 1750. While insome embodiments the light is reflected by the reflector 1752 in otherembodiments the reflector 1752 may be arranged in the housing 1750 suchthat a portion of the interior surface of the housing is exposed insideof the lamp as shown in FIG. 71 such that a first portion of the lightis reflected by the reflector 1752 and a second portion of the light isreflected by a surface portion 1750 a of the housing 1750.

The reflector 1752 is positioned in the housing 1750 to receive lightfrom the LED assembly 130 and to reflect light toward the lens 1754 andmay be mounted over the tower portion of heat sink 149. In otherembodiments the reflector may be mounted to the base 149 of the heatsink, to the reflector 1750 and/or to the tower portion of the heat sink149.

To mount the lens 1754 in the reflector housing 1750 the distal edge1774 of the reflector housing 1750 may be formed to have a channel 1776that surrounds and holds a peripheral edge of the lens 1754. In someembodiments, the lens 1754 may be located in the reflector housing 1750and the edge 1774 of the reflector housing 1750 may be rolled to createthe channel 1776 that surrounds and holds the lens 1754. In otherembodiments the lens may be attached by a separate attachment mechanismincluding separate fasteners, adhesive or the like.

The reflective surface 1756 of reflector 1752 may be shaped to produce adirectional light pattern of a specific shape. For example, thereflective surface 1756 may be formed as a parabolic reflector. In otherembodiments, the reflector may have other shapes to produce a desireddirectional pattern and in some embodiments the formation of thedirectional light pattern may be created by the lens 1754 such that thereflective surface 1756 may have any shape that reflects the lighttoward the lens without necessarily creating a directional beam oflight. The lens 1754 may be used to focus the light reflected from thereflector 1756 to create a beam of light at the desired beam angle. Thelens may comprise, for example, the lens shown in FIGS. 61-64 anddescribed previously herein.

As is evident from the foregoing description, a lamp constructed usingthe primary reflector and the lens 702 may produce light with a beamangle that varies from a wide angle flood pattern to a tightlycontrolled spot pattern. As a result, the construction allows the lampto replace either a wide angle lamp such as a BR lamp or a narrow beamangle lamp such as a PAR lamp.

As previously explained, the reflector 600 as described herein may bepositioned such that the reflector 600 reflects a portion of the lightgenerated by the LED assembly 130. However, at least a portion of thelight generated by the LED assembly 130 may not be reflected by thereflector 600. At least some of this light may be reflected by thereflective surface of the enclosure. Some of the light generated by theLED assembly may be projected to the lens portion without beingreflected by the reflector or the enclosure.

In one embodiment, the reflector housing 1750 is formed with adownwardly extending cylindrical flange 1764 at a first end thereof. Theflange 1764 has an annular shape such that the tower portion of the heatsink 149 and the LED assembly 130 may be inserted through the aperture1766 into the interior of the reflector. The flange 1764 is seated onthe peripheral external surface of the heat sink 149 such that theflange and heat sink are thermally coupled. In one embodiment thethermal coupling is created by direct surface to surface contact betweenthe heat sink and the reflector housing where the inner surface of theflange 1764 and the surface of the heat sink are in good surface tosurface contact such that heat may be transferred from the heat sink tothe reflector. While in the illustrated embodiment, the flange 1764 ofthe reflector housing 1750 and the surface of the heat sink 149 are indirect surface to surface contact with one another, intervening elementsmay be present provided efficient thermal transfer occurs between theheat sink 149 and the reflector housing 1750. For example, thermaladhesive, a metal layer or the like may be disposed between the heatsink 149 and the reflector housing 1750. In this embodiment, the finsassociated with the heat sink 149 may be eliminated. The flange 1764 andheat sink may have generally cylindrical shape; however, the reflectorand heat sink may have a variety of shapes.

To attach the reflector housing 1750 to the heat sink 149, the flange1764 is disposed over the heat sink 149 and is secured thereto by anattachment mechanism. In one embodiment the attachment mechanism maycomprise a friction fit where aperture 1766 of flange 1764 defines aninternal dimension (e.g. diameter) that is slightly smaller than theexternal dimension (e.g. diameter) of the heat sink 149 such that theflange 1764 may be forced over the heat sink 149 to create a tightfriction fit. A lead-in may be provided on the flange 1764, the heatsink 149 or both to facilitate the force fit. For example, the lead-inmay comprise the flange 1764 having a slightly larger diameter openingat the distal end thereof that tapers to a slightly narrower diameteropening toward the interior of the reflector housing. As the heat sink149 is inserted into the flange 1764 the slightly larger opening allowsthe flange 1764 to receive the heat sink. As the heat sink 149 isinserted fully into the flange 1765 the tapering of the flange creates atight friction fit between flange and the heat sink. In otherembodiments, the flange 1764 may be fit over the heat sink 149 andheated such that the heat causes the flange 1764 to shrink to clamp theheat sink in the flange. In still other embodiments a crimping operationmay be used where the flange 1764 may be fit over the heat sink 149 andcrimped or swaged to mechanically clamp the heat sink. In still otherembodiments a separate attachment mechanism such as screws, rivets,adhesive welding, brazing or the like may be used. As previouslyexplained with respect to FIGS. 66 and 67, buttons or nubs may be formedon the peripheral surface of the heat sink. The buttons or nubs may beformed integrally with the heat sink or may be attached to the heatsink. The nub or buttons are inserted through holes in the flange 1764such that they are exposed to the exterior of the reflector. The nub canthen be deformed or smashed to clamp the flange against the heat sink.

Although specific embodiments have been shown and described herein,those of ordinary skill in the art appreciate that any arrangement,which is calculated to achieve the same purpose, may be substituted forthe specific embodiments shown and that the invention has otherapplications in other environments. This application is intended tocover any adaptations or variations of the present invention. Thefollowing claims are in no way intended to limit the scope of theinvention to the specific embodiments described herein.

1. A lamp comprising: an enclosure comprising a reflector and a lens,the reflector made of thermally conductive material; a base; at leastone LED located in the enclosure and operable to emit light whenenergized through an electrical path from the base; a heat sinkcomprising a heat dissipating portion that is at least partially exposedto the ambient environment and a heat conducting portion that isthermally coupled to the at least one LED, the reflector being thermallycoupled to the heat sink and being exposed to the exterior of the lampsuch that heat from the heat sink may be dissipated to the ambientenvironment at least partially through the reflector.
 2. The lamp ofclaim 1 wherein the reflector is made of metal.
 3. The lamp of claim 2wherein the metal is aluminum.
 4. The lamp of claim 1 wherein thereflector comprises a reflective surface that generates a directionallight pattern.
 5. The lamp of claim 4 wherein the reflective surface isparabolic.
 6. The lamp of claim 1 wherein the reflective surface ismetalized.
 7. The lamp of claim 1 wherein the reflector is secured tothe heat sink.
 8. The lamp of claim 7 wherein the reflector is securedto the heat sink using deformable nubs.
 9. The lamp of claim 7 whereinthe nubs are inserted through apertures in the reflector and aredeformed to create a head that retains the reflector against the heatsink.
 10. The lamp of claim 7 wherein the nubs are formed integrallywith the heat sink.
 11. The lamp of claim 1 wherein a secondaryreflector reflects light from the at least one LED to the reflector. 12.The lamp of claim 11 wherein the secondary reflector is located in achamber formed by the reflector and the lens.
 13. The lamp of claim 11wherein the secondary reflector is located inside of the lens.
 14. Thelamp of claim 13 wherein the secondary reflector is inserted molded inthe lens.
 15. The lamp of claim 1 wherein the heat sink extends betweenthe enclosure and the base.
 16. A lamp comprising: an enclosurecomprising a reflector housing made of a thermally conductive materialand a reflector located in the enclosure; a lens for emitting light fromthe enclosure; a base; at least one LED located in the enclosure andoperable to emit light when energized through an electrical path fromthe base; a heat sink comprising a first part that is located inside ofthe enclosure and that is thermally coupled to the at least one LED anda second part that is thermally coupled to the first part; the reflectorhousing being thermally coupled to the heat sink and being exposed tothe exterior of the lamp such that heat from the heat sink may bedissipated to the ambient environment at least partially through thereflector housing.
 17. The lamp of claim 16 wherein the reflectorhousing is made of metal.
 18. The lamp of claim 17 wherein the metal isaluminum.
 19. The lamp of claim 17 wherein the reflector comprises areflective surface that generates a light pattern.
 20. The lamp of claim16 wherein the reflector housing comprises a flange that surrounds aportion of the heat sink.
 21. The lamp of claim 20 wherein the flange issecured to the heat sink using a friction fit.
 22. The lamp of claim 20wherein the flange is heat shrunk over the heat sink.
 23. The lamp ofclaim 20 wherein the flange is crimped to the heat sink.
 24. The lamp ofclaim 20 wherein the flange is swaged to the heat sink.
 25. The lamp ofclaim 19 wherein the heat sink is disposed between the enclosure and thebase.
 26. The lamp of claim 16 wherein the at least one LED comprises aplurality of LEDs arranged such that the plurality of LEDs are disposedabout the periphery of the first part in a band and face outwardlytoward the enclosure to create a source of the light that appears as aglowing filament.
 27. The lamp of claim 26 wherein at least selectedones of the plurality of LEDs emit light laterally.
 28. The lamp ofclaim 16 wherein further comprising a clamping structure for clampingthe at least one LED to the heat sink.
 29. The lamp of claim 28 whereinthe clamping structure comprises a pair of extensions on the LEDassembly that engage mating receptacles formed on the heat sink.
 30. Thelamp of claim 28 wherein the plurality of LEDs are mounted on a submountwhere the clamping structure comprises a pair of extensions extendingfrom the submount that engage mating receptacles formed on the heatsink.